The Science of Evidence

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1Forensic Science and Criminalistics

Associated Press

Learning Objectives After reading this chapter, you should be able to do the following:

▪ Define forensic science and how it contributes to a case, as well as explain the CSI Effect and the scientific method.

▪ Summarize the history of forensic science and contributors to the field.

▪ List and describe some forensic science specialties.

▪ Identify the elements of a forensic investigation, how physical evidence can be produced, and forensic analysis.

▪ Describe the work and work product of a forensic scientist.

▪ Describe the U.S. court system, and the key rulings on physical evidence admissibility through expert testimony.

▪ List and discuss major issues in forensic science today.

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5Forensic Toxicology

Jochen Tack/imageBROKER/SuperStock

Learning Outcomes After reading this chapter, you should be able to

▪ Describe the types of cases that toxicologists analyze.

▪ Identify different poisons and how they are sampled.

▪ Explain how officers recognize drugs and alcohol in the field and how they obtain samples for the toxicologist.

▪ Discuss how toxicologists test blood and urine samples for drugs and alcohol.

▪ Describe the drugs used in drug-facilitated sexual assault and how they are analyzed.

▪ Explain the purposes of forensic urine drug testing and how it is done.

Section 5.1Toxicology Cases

Introduction Poisons have been present throughout human history. Poisoning can be accidental. For instance, someone can eat the wrong plant, mushroom, or fish and die. However, poison- ings can also be planned. Poisons derived from plant extracts have been used in executions; Socrates suffered this fate. He was found guilty of crimes against the state and was given a cup of hemlock to drink. In the past, if you wanted to kill an enemy, there were preparations available that could complete the task. Today poisons are not used as often as instruments of homicide. However, methods of analysis have been found that can determine the presence of toxins in the body and can assist the courts in determining if a person was indeed poisoned or under the influence of a toxin or intoxicating compound.

In today’s world, we come in contact with tens of thousands of chemicals. Many are not harm- ful, but there are many others that are. We discussed drugs in Chapter 4, so we are aware that drugs can cause death if taken in overdose quantities. In fact, nearly every drug can be fatal if enough is consumed. Essentially, this makes almost every drug a poison. Even consumption of excessive water can deplete essential electrolytes in the body and cause death.

An interesting point can be derived from this knowledge: It is the dose that makes a poison. This means that if taken in small enough amounts, some poisons can be used as drugs. This has been the case for many years. For example, arsenic was previously used to control rats and other vermin populations, but it was also used at one time in some Chinese homeopathic medicines in very low doses. Anticancer drugs are poisons that are designed to kill many can- cer cells while killing relatively few healthy cells. Toxicology, therefore, is the study of drugs and poisons or toxins and the way they affect the body. It comprises knowledge from two dis- ciplines—pharmacodynamics, which studies the way drugs act on the body in both positive and negative ways, and pharmacokinetics, which studies how the body acts on drugs. These disciplines and the information gained from the analysis of samples taken during investiga- tions by law enforcement can be used in court cases to help the trier of fact come to a conclu- sion about that case. This science is known as forensic toxicology.

5.1 Toxicology Cases Forensic toxicologists always have a monumental task before them in finding toxic substances and poisons in the body, quantitating the level in the system, and determining possible effects, such as the increasing amount of impairment as individuals consume more alcohol and raise their blood alcohol concentration (BAC). The toxicologist will usually engage in analysis of two types of cases. The first type involves poisonings, both accidental and intentional. The second type involves people who use illicit drugs in a recreational manner or victims who have been given drugs without their knowledge. Those involve issues in which humans are under the influence of one or more compounds that impair their ability to perform tasks (human performance cases). Such cases are typical for the forensic toxicologist and involve driv- ing under the influence of alcohol (DUI) or driving under the influence of drugs (DUID). The toxicologist performs analyses that can find many more compounds than the drug chemist. A toxicologist also searches for compounds in blood, urine, or other biological samples, where the concentration of compound present is in the parts per million range, and the interfering components in the sample can be in the hundreds. In comparison, a drug chemist looks for a drug in a tablet, capsule, powder, or plant material, where the amount of drug is determined

Section 5.2Poisons

as a percentage of the total weight of the sample, and there are relatively few interfering compounds or diluents. Another factor in a toxicologist’s work is metabolism. Metabolism is the body’s way of breaking down a poison or drug into compounds called metabolites. Metabolites are compounds that can be eliminated from the body more efficiently than the parent compound (the poison or drug). In order to facilitate elimination, drugs are usually made more water soluble so they can be deposited in the urine. Once in the urine, they can be eliminated from the body. There are other ways to get rid of a drug, but transforming it into a metabolite for removal is the most common. If metabolism has progressed far enough, the original drug or toxin will not be found in the body. Instead, the analyst must search for one or more metabolites of the drug. As we will see, all of these factors make forensic toxicology a very interesting job.

The majority of cases submitted for forensic toxicological analysis will include two classes of compounds. Those classes are (a) drugs of both the licit and illicit kind and (b) volatile sub- stances, such as ethanol and inhalants. Other toxins may be encountered, but to a much lesser extent. These include gases, metals, pesticides, and other miscellaneous compounds. Cases and samples involving all of these compounds will make their way to a forensic toxicology laboratory from a coroner’s office or medical examiner’s office and through law enforcement personnel.

There are also privately run laboratories that perform forensic toxicology testing in support of drug-use prohibitions, such as in certain occupations or in athletic competitions. This aspect is discussed later in the chapter.

5.2 Poisons Historical poisons are encountered by the forensic toxicologist on a limited basis, but there are several types of poisons. Most will likely be seen in general circumstances. Heavy metals, such as arsenic, mercury, and lead, are often encountered by people because of accidental ingestion. There have been cases of homeowners removing lead-based paint with hair dry- ers without adequate ventilation; these people have come down with lead poisoning from inhaling the fumes generated by the heat of the hair dryer. Children have succumbed to lead poisoning from eating chips of lead-based paint. Family members and their pets have experi- enced arsenic poisoning after contact with older rat poisons. Other metals, such as thallium, cadmium, cobalt, and selenium, are included in this class, though they are not often encoun- tered or easily obtained and would most likely be involved in a case of intentional poisoning.

In these cases, blood and urine samples can be tested by the toxicologist. The principal test utilized is atomic absorption spectroscopy (AA), which is sensitive to the µg/L level. Scientists

Think About It

While many forensic toxicology cases involve DUI and DUID—and these seem like pretty straightforward trials—forensic toxicologists spend a great deal of time in court on these cases. Why do you think they are called to court so often?

Section 5.2Poisons

measure everything in metric system units: “µ” means micro, or one millionth; “g” stands for grams. There are about 28 grams in an ounce. “L” means liter, which is around a quart.

New testing methods have made it possible for other samples to be tested. Hair testing for some of the heavy metals, though not lead, can allow the toxicologist to determine whether the dosing was acute, or one time only, or happened over a period of time, called chronic dos- ing. Analysis of tissue samples postmortem would also be completed using AA, and it could be used to quantitate the level in the body to determine if it was metal poisoning that killed the victim.

Cases involving toxic substances have also been seen. For instance, in the early 2000s, ethyl- ene glycol, a substance once commonly found in radiator fluid, was responsible for a large number of poisonings, some accidental and some not. The Georgia Poison Control Center, for instance, had 235 cases in 2004 (Morgan, Geller, & Kazzi, 2011). The ethylene glycol is metab- olized in the body to form a toxic substance that can be lethal. The ethylene glycol has been replaced in most of these fluids with propylene glycol to try and eliminate this type of poison- ing, or in some cases a very bitter flavoring has been added to prevent accidental ingestion. As of 2012 all producers of antifreeze for automobile use have either switched to propylene gly- col or added the bitter flavoring agent. Interestingly, there have been three recent murder mysteries in which the killer used ethylene glycol in radiator fluid as the poison of choice.

Recall from Chapter 1 that Mathieu Joseph Bonaventure Orfila is often called the father of forensic toxicology. In 1840 Dr. Orfila became involved in one of the most famous (or infa- mous) cases of murder by poisoning in history, in which Marie Lafarge was convicted of poi- soning her husband, Charles, with arsenic.

Think About It

There is a wealth of knowledge communicated through the media and Internet, including information on the use of poisons. Do you feel that placing information of this nature on television and the Internet allows people too much access to informa- tion that can prove to be harmful to people?

Case Illustration: Toxicology and Murder—in the Beginning: The Lafarges

Marie married Charles Lafarge in 1839. Although she did not come from an aristocratic background, she had been sent to the best schools and had moved in the best circles. She agreed to marry Charles under the mistaken impression that he owned property and had a successful business. In fact, he was marrying Marie for her dowry, to help pay down his debts.

They moved to a run-down house owned by Charles. She was quickly disillusioned about this arrangement and encouraged Charles to go to Paris to try to raise money. While he

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Case Illustration: Toxicology and Murder—in the Beginning: The Lafarges (continued)

was away in Paris, Marie sent him a Christmas cake. After eating a piece of it, he became violently ill. He discarded the remainder of the cake, but did not think about seeing a doc- tor; he thought the cake had spoiled in transit. He still did not feel well after returning home. Marie prepared his meals during this time, and he again fell ill. The family doctor thought the symptoms were “cholera-like” and was not suspicious when Marie asked him for a prescription for arsenic to kill the rats that were disturbing Charles at night. Charles’s health deteriorated rapidly, and he eventually died. His family, and others who had come to keep watch and help him, became suspicious of Marie. She had been observed stirring a white powder into food and drink intended for Charles. A doctor that was consulted close to the time Charles died began to suspect poisoning, but it was too late.

One of Charles’s brothers, whose suspicions had been aroused, contacted the local police, and a magistrate came to do an inquiry. He took possession of some food items that remained, which could contain a poison. He learned that Marie had purchased arsenic not long before Charles had received the cake in Paris and again after he returned home. Marie’s gardener confirmed that she had given him arsenic to make a paste to kill rats. This paste was found around the house, but it did not appear to have been disturbed by rats. The magistrate also asked Charles’s local doctors if they could perform a new test for arsenic that he had heard about: the Marsh test. The doctors agreed but did not know about the test’s intricacies. They used older methods to test Charles’s stomach contents taken at autopsy and obtained inconclusive results. Nevertheless, they reported arsenic present. One of the people tending to Charles had taken Marie’s box, from which people had seen her taking the white powder for Charles’s food and drink, and it was turned over to the magis- trate. Arsenic was found in the box. In addition, the arsenic paste that had been placed in the house for the rat problem was found to be a mixture of flour, water, and baking soda.

Marie was put on trial for murder. One of Marie’s lawyers knew Dr. Orfila. He submitted the local doctors’ arsenic testing results to Orfila and asked for an opinion. Orfila submitted an affidavit to the trial court stating that the tests had been conducted poorly and that the result meant nothing. When the local doctors testified about the arsenic in Charles’s body, the lawyer read Orfila’s affidavit informing the court about the Marsh test and insisted that he be called to do the test and as a witness. Prosecutors were confident of Marie’s guilt and said they would agree to the testing, but they did not see the necessity of calling Orfila (who was the acknowledged expert on the Marsh test in Europe at the time). The judge agreed and ordered that local pharmacists conduct the testing. They reported not finding any arsenic in the stomach contents taken at autopsy. Charles’s body was then exhumed and new specimens taken. The pharmacists again failed to find arsenic. Marie seemed to be vindicated.

However, the prosecutor learned from Orfila’s writings that arsenic can leave the stom- ach through normal digestive processes and thus not be present in the contents. He also remembered the saved food items that Marie had given to Charles. He asked that they be tested. The defense, now confident about their case, agreed. This time, though, the pharma- cists came back and said there was a large amount of arsenic in the food items. The pros- ecutor again asked the judge to permit Orfila to come in and settle the matter, since there had been contradictory results. The defense more or less had to agree to this, having con- sulted Orfila first. Orfila conducted his tests in the presence of the pharmacists and found that arsenic was present in specimens taken from Charles’s body. The defense team sought to call an opposing expert, François Raspail, who had opposed Orfila in court at other

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Section 5.2Poisons

measure everything in metric system units: “µ” means micro, or one millionth; “g” stands for grams. There are about 28 grams in an ounce. “L” means liter, which is around a quart.

Think About It

Case Illustration: Toxicology and Murder—in the Beginning: The Lafarges

They moved to a run-down house owned by Charles. She was quickly disillusioned about this arrangement and encouraged Charles to go to Paris to try to raise money. While he

(continued on next page)

Case Illustration: Toxicology and Murder—in the Beginning: The Lafarges (continued)

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Section 5.2Poisons

This was a spectacular case in the annals of criminal justice. People were divided on whether Marie was guilty. It was also one of the first cases pitting experts against one another in the courtroom—something that is quite common today.

Poisoning is now infrequent in murder cases. A couple of centuries ago, it was used often by the aristocracy to get rid of their enemies. A modern murder by poison took place in 2000 in San Diego, California. This case is intriguing because it involves employees of the medical examiner’s forensic toxicology laboratory. For more on this case, see the Case Illustration box later in this section.

Pesticides Pesticides are not usually seen in forensic toxicology cases. A common class of pesticides is the organophosphates; these compounds include parathion and diazinon. Most of these cases involve accidental exposures. Should a case be seen that is suspicious, blood and urine sam- ples can be analyzed in the forensic toxicology laboratory.

Chromatographic techniques can provide preliminary information about a sample through separation of the different components of a mixture. If you put a drop of ink near the bottom of a piece of paper and then dip the paper in water, the water will be absorbed and travel up the paper. When the water hits the ink, some of the pigments will continue upward with the water, while others remain behind. As the water continues to travel up the paper, you can see separation of the ink pigments. This works the same way with forensic samples when put through instrumentation that is often used. By separating a mixture such as urine into its individual components and comparing these to known pesticides, we can say that a pes- ticide could be present in the urine, and if so, it might be a particular pesticide as opposed to many others.

Mass spectroscopy will then be used to conclusively identify the pesticide that was ingested by the victim and found in the urine. Remember from Chapter 4 that mass spectroscopy can give molecular information that will allow the scientist to say without doubt that a partic- ular pesticide, such as malathion, is present, as opposed to any other pesticide that exists. Hospitals can determine this class of compound is involved based on symptoms, including salivation, lacrimation (tears), excessive urination, diarrhea, nausea, and vomiting. Testing is then completed to determine if organophosphate class compounds are present. Should the circumstances of the poisoning be suspicious, law enforcement will be called. Samples should be collected with proper chain of custody and sent to the forensic science laboratory.

Case Illustration: Toxicology and Murder—in the Beginning: The Lafarges (continued)

times. Unfortunately for Marie, Raspail was late, and the trial ended. Marie was convicted and sentenced to life imprisonment. Suffering from tuberculosis, Marie was released in 1852 but died the same year.

Reflect On It In what ways do you think this case would be different today, in terms of determining the pres- ence of arsenic in Charles’s body, the court proceedings, and the verdict?

Section 5.2Poisons

Carbon Monoxide Carbon monoxide (CO) is encountered mainly in accidental deaths. This odorless, colorless gas binds to hemoglobin (the protein in red blood cells that carries oxygen) so tightly that it cannot be easily displaced. As more and more hemoglobin is rendered useless by binding to CO, oxygen deprivation will set in and can cause death. Most of the approximately 500 deaths from CO in the United States each year are due to malfunctioning flame heaters and a lack of CO detectors in homes, and they are termed unintentional deaths (CDC, 2007). Suicide by CO poisoning using automobiles used to be common, though this is becoming less popular as other methods of CO poisoning, such as by charcoal, have been found (Schmitt, Williams, Woodard, & Harruff, 2011). Carbon monoxide is formed when organic fuels are burned with too little oxygen present to form carbon dioxide (CO2). Levels of less than 1.5% CO in the air can be lethal within minutes. In the lab, a CO-oximeter will be used to measure the level of carboxyhemoglobin in the blood to determine if the cause of death was CO poisoning.

Other Gases Toxicology laboratories are encountering other gases in samples from law enforcement agencies. Many of these submissions are due to intentional inhalation of various substances for the purposes of getting high. Included in this group are the inhalants discussed in Chapter 4. These are the nitrites and nitrates; anesthetic gases like nitrous oxide and halo- thane; and the fluoro- and chlorocarbon compounds, such as difluoroethane, found in office supplies and pressurizers for food products. These compounds are easily purchased and abused. Users inhale the contents as they spray them from the can. The ingredients enter the bloodstream very quickly through the lungs. The effects are similar to central nervous system depressants. An officer on the scene may find a user unresponsive, but he or she will revive in minutes, and the compounds will clear from the bloodstream very quickly. Due to the rapid clearing of the compounds from the system, obtaining samples for prosecution of cases is difficult, since most of the drug will clear from the user’s system on the way to a collection site such as a hospital.

These compounds do not show up in Breathalyzer testing and will not be seen in the urine under normal testing, so a blood sample is best for cases involving inhalants. In the labora- tory, the sample will be tested using headspace gas chromatography with mass spectroscopy. This is the same technique used to find ethanol in the blood; it can easily differentiate and conclusively identify various inhalants for the courts.

Illicit Drugs and Medications Illicit drugs and medications are commonly seen in toxicology cases. These also involve sam- ples taken from living beings and samples taken postmortem. In the case of drugs, testing will include the use of chromatography of various types, color tests, and immunoassay as the preliminary testing to determine the classes of drugs that might be present. Extraction of the sample is completed to purify the sample. Final identification of the drugs is accomplished with mass spectroscopy as the conclusive test. Blood and urine samples are the most com- mon, though hair testing is on the rise. In postmortem cases, other samples will be collected, including vitreous humor (fluid in the eye) and possibly tissue samples. While collecting fluid from the eye may seem unusual or even disgusting, for the toxicologist, the vitreous humor is a sample that is cleaner than samples like blood or even urine, because there are fewer

Section 5.2Poisons

bacteria and interfering compounds contained in the fluid. These samples will be collected by the medical examiner or forensic pathologist at autopsy.

The collection of gastric contents may seem like an obvious step from many of the forensic television shows, but the forensic toxicologist will not usually look for the victim’s last meal. Instead, he or she will look for drugs or poisons that may have been used acutely to cause death. Sometimes, there will be the remnants of tablets or capsules in the gastric sample. These are easily and quickly analyzed and can indicate what the toxicologist will find in the blood. Additionally, gastric contents can be analyzed to find drugs of abuse that are not in standard dosage forms. For instance, GHB might be found in a victim who died shortly after administration of the drug.

Multiple blood samples are often taken at autopsy because of a phenomenon called postmor- tem redistribution. This can be seen if the victim has been deceased for a period of time, presenting the toxicologist with significant challenges. Drug concentrations in organs of the body will be higher than the blood concentration until absorption and distribution take place. Upon death, this distribution cannot be completed. The drug will start diffusing through the body from the area of highest concentration toward a lower concentration. What this means is that a blood sample taken from the chest area might have a very high concentration of a drug, because of redistribution from the gastrointestinal tract into the bloodstream, while blood taken from the leg would have a lesser concentration. Toxicologists must be able to ana- lyze all presented samples to determine how much redistribution has taken place and what might have been an effective concentration in the blood when the victim died.

The toxicologist will usually begin with a screening of the urine sample to find out what classes of drugs could be present. The reason for starting with urine is that after drugs are taken in to the body, they are distributed through the blood to the tissues. After the drug has acted on the body, it is metabolized and eventually delivered to the kidneys to collect in the urine. Therefore, the urine will have a higher concentration of drug than the rest of the body. This makes detection of drugs in urine much easier than in other body fluids or tissues. Sampling for many immunoassay tests takes place directly on the urine with little or no pretreatment. Immunoassay tests can simultaneously test for many classes of drugs, in very little time and with minimal sample use, allowing the toxicologist to determine what classes of drugs could possibly be present in the individual. These tests rely on exposing a sample to reagents that react with drugs or the metabolites of drugs that can be found in the urine after consumption of drugs. For instance, there is a reagent that, in the presence of benzoylecgonine, a metabo- lite of cocaine, will give a reaction that can be read by the instrument. The analyst can then determine if the sample should be tested further to confirm the presence of cocaine and its metabolites. There are many reagents that can test for a large variety of drugs of abuse. This testing is rapid and uses very little of the sample.

At the same time the urine is screened for drugs, the blood can be tested for volatile sub- stances such as ethanol, methanol, isopropanol, the inhaled gases, and acetone. The test used for this analysis is called headspace gas chromatography. A sample of the blood is added to a vial with a compound called an internal standard. This internal standard is a compound that behaves on the instrument very much like the compounds the toxicologist is analyzing. The internal standard is not likely to be found in a sample, for a variety of reasons, including the fact that it might not give a reaction in the body, is not yet approved for use by the FDA, or might act like the drug on the instrument while not actually being a drug. This compound

Section 5.2Poisons

helps standardize analysis so quantitation and identification can easily be completed. The sample with the internal standard is sealed in its vial. The vial at this point is only partially filled, with significant air above the liquid. This is the headspace. The vial is heated so a small amount of any volatile substance can evaporate into the air above the liquid. Each volatile substance has a concentration that will evaporate into the headspace relative to the concen- tration left in the blood at the temperature used to heat the sample. After heating and equili- bration, a specific amount of the headspace is withdrawn from the vial and placed onto the gas chromatograph. All of the volatiles are separated in the gas chromatograph and, after passing through a detector, are plotted on a graph. This graph will let the analyst determine the identity of the compound based on the time it took to get through the column to the detec- tor; it also allows the analyst to quantitate the amount based on the size of the peak.

After this analysis, other samples taken from the blood may be used to quantitate other drugs that may be present as indicated by the urine analysis. These tests require extractions of the blood to clean up the sample for analysis, followed by instrumental analysis to identify and quantitate the amount of drug present in the blood. Remember, only the drug in the blood has the ability to interact with tissues and let the drug have an effect.

Case Illustration: Toxicology and Murder—Modern Day: Rossum v. Patrick

Kristin Rossum was accused and convicted of poisoning her husband, Greg, using fentanyl she had stolen from the medical examiner’s toxicology laboratory, where she worked as a toxicologist. As you may recall from Chapter 4.4, fentanyl is a synthetic narcotic analgesic, about 100 times more potent than morphine.

Kristin worked in the San Diego County Sheriff/Coroner Toxicology Laboratory. At some point, she began an affair with Michael Robertson, the chief of toxicology, who was also married at the time. Kristin was a drug abuser who stole drugs from the workplace to feed her habit. Kristin’s husband learned about the affair and threatened to expose her and her drug use if she did not quit her job.

On the day of Greg’s death, Kristin called 911. Responding paramedics found him in the middle of the living room. His body had been sprinkled with red rose petals, and a wed- ding picture had been placed nearby, a setting similar to a scene from one of Kristin’s favorite movies. Kristin’s credit card had been used to buy a similar rose. The paramedics took Greg to a hospital, where he was pronounced dead.

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Dennis Poroy/Associated Press Kristin Rossum being escorted to the processing room after being convicted of the murder of her husband.

Section 5.3Drug and Alcohol Recognition in the Field

The protocols discussed are used in the most common of toxicological cases, such as DUI and DUID cases. Today these cases constitute a majority of the samples seen by toxicologists. Make no mistake, poisonings and deaths are seen as well, but DUI and DUID cases are the most common. How do these cases make it to the laboratory? The most common route is through a traffic stop or an accident. Officers determine if alcohol or drugs may be involved, and samples will generally be collected at a hospital and taken for testing by the laboratory. But how is that determination made? This will be answered in the next section on how to recognize drug and alcohol use in the field.

5.3 Drug and Alcohol Recognition in the Field Police officers may receive training to recognize if drugs or alcohol might be present in a person. Some states have what is called the drug recognition expert (DRE) program. Not all officers are trained as DREs. However, the program is expanding, so more officers are receiv- ing this training, which goes beyond the standard to enable officers to determine when a

Case Illustration: Toxicology and Murder—Modern Day: Rossum v. Patrick (continued)

Police questioned Kristin weeks after Greg’s death. There was a conflict of interest with the toxicology laboratory at her place of employment, so the toxicology testing of specimens from Greg’s body was outsourced. The lab reported high levels of fentanyl (above fatal lev- els) along with clonazepam and oxycodone at therapeutic levels (both of these drugs are legal by prescription). The investigation went on to uncover Kristin’s methamphetamine use and a large quantity of fentanyl missing from the coroner’s office. Kristin was charged with and tried for murder; the state’s allegation was that she killed Greg by administering to him a fatal dose of fentanyl.

The evidence was circumstantial, but Kristin was convicted. The defense had argued that Greg was suicidal and had poisoned himself. The jury did not agree. Kristin was sentenced to life without the possibility of parole.

Kristin appealed for a new trial in federal court but was turned down. She then appealed to the Ninth Circuit Court of Appeals. A three-judge panel of that court was ready to reverse the lower court and grant her petition, but they withdrew their opinion and replaced it with a one-paragraph statement that a newly decided U.S. Supreme Court case, Harrington v. Richter (2011), controlled their decision.

Kristin’s appeal was based on ineffective counsel at trial. The argument runs that her defense attorneys should have pursued some toxicological issues that they did not and which, if they had, might have resulted in a different outcome. One issue is whether the admittedly sublethal quantities of clonazepam and oxycodone found in Greg’s body might have caused his death by way of synergistic drug action—acting together in a way that was more powerful than that of either drug separately at the same levels. Another issue raised on appeal was the possibility that the fentanyl was administered postmortem. An expert hired by Kristin noted that the postmortem specimens were not tested for fentanyl metab- olites, and as a result, it was not certain that he had ingested the drug before his death.

Reflect On It Was there sufficient evidence to convict Kristin Rossum of poisoning Greg? Why or why not?

Section 5.3Drug and Alcohol Recognition in the Field

suspect has used a drug and what class of drug it could be. Officers do not try to determine the specific drug, only a general group. The groups include depressants (including alcohol), stimulants, hallucinogens, and also phencyclidine, opiate and narcotic drugs, cannabis, and inhalants. Officers will not consider common drugs, such as aspirin, in their determinations. They can only determine if an impairing, abused drug might be present. The information gained by the officer at the scene can be used by the toxicologist to assist in analysis. Remem- ber, however, that the toxicologist will only use this information as an aid. The analysis is not tailored to the results of the officer’s investigation and report.

The following example will take us through a complete toxicology case in which the charges will be DUI and DUID. An officer responds to the scene of a simple accident, where a car has struck a telephone pole. Upon questioning the driver, the officer notices what seems to be the odor of an alcoholic beverage on the driver’s breath. Something to note is that ethanol has no odor; instead, it is the other components of the alcoholic beverage, such as tannins, oils, and additives, that contribute to those smells. At this point, the officer may ask the suspect to submit to field sobriety tests. These are called in some circles psychophysical tests or divided attention tests. The officer is trying to determine if the suspect could be impaired. The three tests normally used in the standardized field sobriety tests (SFSTs) are the walk and turn test, the one leg stand test, and the finger to nose test (U.S. Department of Transportation National Highway Traffic Safety Administration, 2001).

Additionally, the suspect might be observed by the DRE. Certain aspects of behavior and appearance indicate the possibility of drug use. These include the way the suspect answers questions. Does the person answer the officer’s question or exhibit a stream of conscious- ness talking that bears no relation to the question? Does the person appear to be disheveled or unable to stay alert? All of these characteristics can be used by the DRE to determine if a suspect is under the influence of a drug, and if so, the class to which that drug belongs.

If the person being observed took a depressant, he or she may be lethargic and slow to respond or may fall asleep at inappropriate times. Officers have observed suspects who were placed in a squad car fall asleep even after an accident. If the person being observed has pin- point pupils, this could indicate an opiate as opposed to any other depressant, as most other depressants do not cause this condition. It is often very easy to determine if inhalants are the problem. Remember, inhalants depress the central nervous system, causing drowsiness and sleep. Since these are so fast acting, there is usually evidence in the immediate vicinity, such as the cans containing the gases. These should be collected as evidence, because by the time officers take the person to a sample collection facility, he or she will appear normal and the drug will have mostly cleared from the system.

If the person has taken stimulants, he or she may be very active and energetic or, depending on the stimulant, uncooperative and argumentative. Hallucinogens can cause similar symp- toms, but the behavior of a person using this class of drug may be more bizarre, and their affect and response to questioning will be less coherent. The officer may check for horizontal and vertical gaze nystagmus, uneven tracking of the eye, if the presence of a hallucinogen, in particular PCP, is a possibility. The officer will ask the person to follow an object as it is moved up and down and left and right in front of him or her. Normally, the eye can track smoothly. It has been found that people using PCP cannot track smoothly up and down. Other drugs can cause uneven tracking in the side-to-side testing. Lack of convergence, or the inability of a person’s eyes to converge (cross) on a subject in front of his or her nose, can also be a symp- tom of certain drugs. Table 5.1, the drug recognition expert matrix, is a helpful tool for

Section 5.3Drug and Alcohol Recognition in the Field

evaluating a person in the field, although it should not be used to conclusively identify a drug in a person’s body, since only scientific testing can do that.

Adapted from "Table 2: Signs typically produced by drugs in categories shown," from "The drug evaluation classification program: Using ocular and other signs to detect drug intoxication," by E. M. Kosnoski, R. L. Yolton, K. Citek, C. E. Hayes, and R. B. Evans, 1998, Retrieved from https://www.researchgate.net/publication/13697760_The_Drug_Evaluation_Classification_Program_using _ocular_and_other_signs_to_detect_drug_intoxication

This test could let the DRE know that the suspect has taken PCP and great care should be taken with the individual, as many PCP users have violent episodes. Additionally, PCP is a dissociative anes- thetic, which means the suspect will not feel pain normally. This can lead to a very dangerous situation for officers and any- one else in the area. Other hallucinogens, including cannabis, do not have this same effect.

If the suspect scores poorly on the SFST, the DRE may have a good indication of the drug present in the suspect. He or she will be further interviewed and asked to take a Breathalyzer test if alcohol appears to be present without other drugs, or a blood and urine test if there is an indication that drugs other than alcohol are present. Breathalyzer test units today accurately record the alcohol concentration in the breath. There are many

Table 5.1: Drug recognition expert matrix

Horizontal gaze nystagmus

Present Present Present None None None None

Vertical gaze nystagmus

Present Present Present None None None None

Lack of convergence

Present Present Present Present None None None

Pupil size Normal Normal Normal Dilated Dilated Dilated Constricted Reaction to light

Slow Slow Normal Normal Slow Normal Little to none

Pulse Down Up Up Up Up Up Down Blood pressure

Down Up/ Down

Up Up Up Up Down

Body temperature

Normal Up/ Down/ Normal

Up Normal Normal Up Down

Dep re

ss an

Ca nn

ab is

St im

ul an

Hal lu

ci no

ge ns

In ha

la nt

Dis so

ci at

iv e

an es

th et

ics

Nar co

tic a

na lg

es ic

Marion R Walding/Associated Press Some bars are beginning to install Breathalyzer machines on their premises. Do you think this idea would help prevent more people from driving before they are sober?

Section 5.4Additional Drug and Alcohol Testing

restrictions for Breathalyzer testing that are followed to make sure the test is accurate. The individual being tested must be observed for 20 minutes prior to the test to ensure that for- eign materials have not been placed in his or her mouth and that he or she does not belch or vomit. This rule was originally made for the protection of the suspect, to ensure that no raw ethanol was in the suspect’s mouth. The presence of alcohol in the mouth would falsely increase the breath alcohol concentration (BrAC).

In addition to the breathalyzer for alcohol, in the mid-2010s portable handheld machines were introduced that can test for amphetamines, benzodiazepines, cocaine, methamphet- amines, opiates, and THC. An officer takes a swab from inside the suspect’s mouth and inserts it into the machine, and the results are ready in five minutes. These tests screen for recent drug use, not chronic use, and the results have been deemed admissible in court (Strandberg, 2016). This is a much faster and easier way to check if a driver is impaired than taking a sus- pect to a second location for a blood or urine sample. Implementation of this technology is still in the early stages, but perhaps one day it will be as common as a roadside breathalyzer.

5.4 Additional Drug and Alcohol Testing Most people may not be aware, but in most states, when you sign your driver’s license, you are entering into an agreement with the state that if you are stopped for DUI you agree to submit to testing. This has been called “implied consent.” This testing could involve collection of a DUI kit for blood and urine testing, or it could mean Breathalyzer testing. In 2016 the U.S. Supreme Court changed the way blood could be taken (Birchfield v. North Dakota, 2016). Now, if blood is to be taken, a search warrant must be obtained by law enforcement officers, signifi- cantly impacting the original idea of implied consent. Regardless, some kind of confirmation of the presence of alcohol or drugs in the suspect needs to be proven by a laboratory in order to confirm the field testing in court.

The use of Breathalyzer testing and the rules for the administration of the breath test have been changed in recent years by the defense community. Defense attorneys have tried to say, for instance, that because a person had dentures, his or her Breathalyzer test was invalid. This has given rise to myths about beating the Breathalyzer test, including the idea that putting a penny in your mouth can produce a bad result. While it does not interfere with the test, offi- cers do need to be aware of the fact that suspects may try to hide items in their mouth.

In addition, suspects are now taken to a law enforcement facility for a Breathalyzer test instead of using a portable Breathalyzer test (PBT) unit in a squad car. The PBT can be used for probable cause but not as final evidence in a court. The concern is that since the PBT is in a car and exposed to bumps, accidents, and other factors, the calibration may not be correct and the results may not always be accurate.

Instruments must be routinely checked for reliability and calibrated for accuracy. Test admin- istrators are trained to operate, function check, and administer the tests, since this is one of the most routinely challenged aspects of DUI cases. All log books and calibration and function check data must be kept in order to meet these challenges. During the observation period, the suspect will be asked more questions about health, use of alcohol or drugs, and food con- sumption. This will be used in court and by the toxicologist. The answers collected can allow the toxicologist to perform a back extrapolation, which we will discuss later.

Section 5.4Additional Drug and Alcohol Testing

Hospital Blood and Urine Samples If the suspect agrees to a blood draw and gives a urine sample, or if the Breathalyzer test is negative, he or she will often be taken to a hospital for the draw and collection. Blood draws are routine in the case of an accident. The routine hospital blood draw will allow the hos- pital to test serum for alcohol. Serum is the fluid left behind when all of the blood cells are removed. This process concentrates the alcohol in a smaller volume, making it necessary to convert the serum alcohol concentration into a whole BAC. This is easily done, since many studies have concluded that the average serum to whole blood conversion ratio for people is 1.18 to 1 (Charlebois, Corbett, & Wigmore, 1996). To convert, a toxicologist will divide the serum alcohol concentration by 1.18 and obtain the whole BAC.

Sample Collection for the Toxicologist In cases that involve DUI and DUID, chain of custody is assisted by the use of prepared kits from various scientific companies, one of which is Tri Tech, Inc. As you may remember from our discussion in Chapter 2, chain of custody applies to every kind of evidence, and it must document who handled the evidence, who analyzed it, how it was treated, what preparation was done to it before packaging, and where it was stored. Any breaks in the chain of custody can result in the evidence being inadmissible in court.

The blood and urine samples for forensic toxicologists are separate from the hospital samples, and the use of the prepared kits is a necessity. The kits are sealed boxes containing the paper- work and vials necessary for sample collection. When needed, the seal on the box is broken to allow access to the contents. A typical kit contains two vacutainer tubes. These will have gray tops and contain a preservative and an anticoagulant. The preservative keeps the blood from spoiling, and the anticoagulant keeps the blood from clotting. Both are necessary for the toxicologist to test the blood and arrive at a reliable BAC. There are two labels for the blood tubes, on which the name of the suspect, the date and time, the officer’s name, and the name of the individual drawing the blood are written. This can then be placed on the tube to seal it.

The urine collection is accomplished using two plastic bottles in the kit. These bottles are clean and dry and will provide enough sample for testing at the toxicology laboratory. There are labels for these bottles similar to those for the blood tubes that can be used to seal the bottles. The urine collection is accomplished while maintaining the dignity of the suspect. This is often done by a same-sex officer accompanying the suspect to a restroom prepared for sample collection. The suspect is searched to make sure he or she does not have anything that could be used to contaminate the urine sample. The suspect has the privacy of a stall, but the officer is outside to receive the sample immediately after it is placed in the vial by the suspect.

Paperwork is included to provide a history of the incident, be it an accident or traffic stop; sus- pect information, including medications being taken and possible drug or drinking history;

Think About It

What do you think of implied consent? Will the recent ruling damage the ability of officers to confirm impairment of suspects?

Section 5.5Toxicology Laboratory Testing

and a request from the officer to the laboratory indicating what analysis should be completed. While the collection is taking place, the suspect will be examined and observed by medical personnel who can help determine the possible drug class that was ingested by the suspect. This information will be communicated to the officer, and further discussion with the DRE may take place to arrive at the possible cause of impairment. The DRE may compile enough information to write the report that can later be used in the trial. When the collection is com- plete, there is a form for the toxicology laboratory that will let the toxicologist know what is possibly in the blood and urine. Everything will be placed back in the original box, sealed using a label, and sent to the toxicology laboratory.

Transportation of samples to a forensic laboratory should take place as soon as possible. While storage at room temperature for a time is not harmful to the samples, care should be taken to prevent exposure to extremes in temperature. Excessive heat, like storing the sam- ples in the trunk of a car on a hot summer day, will destroy the blood samples and promote growth of bacteria in the urine. Excessive cold weather with temperatures below freezing could cause the blood to freeze and shatter the tubes. Samples can be kept safely in a refrig- erator not used for food as long as proper chain of custody is kept and the refrigerator is in a secure area of the building.

5.5 Toxicology Laboratory Testing Once the evidence has been received in the toxicology laboratory, it will be signed into the laboratory, and each item of evidence will be given a unique identifier. This will prevent any sample mix-up in the future. The evidence will be stored in a locked area under refrigeration. When it is to be analyzed, it will be moved to the testing area. The toxicologist will see the information from the officer’s observations and the medical personnel’s evaluation. This can be used by toxicologists in their analysis to assist in testing, but it will not be the sole basis for their tests. Toxicology laboratories have well-documented rules to determine who can direct a laboratory and who can do the testing (SOFT/AAFS, 2006). The analysts must follow protocol when analyzing evidence. These rules for analysis make sure complete and unbiased testing is done in each case presented. One of the first rules is that the toxicologist should only sample from one blood tube and one urine vial. The remaining sample should be kept in case the defense wants testing completed by their toxicologist.

Analysis is always completed with control samples, as we discussed in Chapter 1.4. These controls are a large part of the quality assurance and quality control process. They are sam- ples from the same matrix (blood or urine) that is being tested. There are several types of controls used in the toxicology laboratory. Positive controls have drugs in them. Analysis of this control lets the toxicologist know that the procedure worked as expected, and if drugs were in the suspect sample, they would be found. Negative controls do not have drugs in them. These samples let the analyst know that the testing worked and there was no contami- nation of samples in the extraction and testing process. Quantitative controls are used if the sample is to be tested for the amount of drug present. These have a known amount of drug present, and after completion of the analysis using these controls, the analyst will know that the process worked and gave the correct value of drug present. If all controls give their proper answer during analysis, the analyst knows the procedure worked from the first step in the extraction process all the way through instrumental analysis.

Section 5.5Toxicology Laboratory Testing

Analysis of Cases The analysis of other samples at the foren- sic toxicology laboratory is much the same as those submitted for drug analysis. Pre- liminary tests indicating possible classes of drugs or poisons that may be present are completed. Finding what is possibly present in a sample is often referred to as qualitative testing. Preliminary testing includes use of color reagents that react based on the possible presence of a drug. Different types of immunoassay tests also provide preliminary information about the classes of drugs that may be present. These tests use a specially designed antibody to react with a drug in the urine or other fluid. When a drug is present, the reaction will yield a product that can be detected and measured in the instrument, letting the analyst know that a certain drug or drug class is present in the sample. After determining what class of drug might be present, confirmatory testing is done to conclusively identify the drug or drugs present. Fol- lowing this, testing to establish the concentration of drugs in the body can be completed. This is called quantitative testing. In every case, qualitative testing is completed because the forensic toxicologist must report what drugs or metabolites were in the suspect’s system to the trier of fact. The completion of quantitative testing depends on the type of case and the individual statutes of the state where the crime was committed.

In every DUI case, a quantitative test will be completed. Each state has a BAC that legally establishes impairment. Because of this, the toxicologist must know the concentration for tes- timony in court. In a case in which a controlled substance is involved, some states have what is called a per se law. This means that the toxicologist does not have to quantitate the con- trolled substance that is present if it is termed a drug of abuse. This is because the per se law deems that any amount of that substance found in the body classifies the suspect as impaired. This includes drugs like cocaine, methamphetamine, PCP, and LSD. Many cases involve pre- scription drugs. Some of these drugs may be controlled, as we saw in Chapter 4, but are not considered drugs of abuse. In cases involving these drugs, toxicologists may quantitate the drugs present if a blood sample is submitted. They will not be able to tell if the person was impaired, but they can obtain a level of drug in the blood. There are three general levels of drug in the body that can be described.

A subtherapeutic level of drug means that there were drugs in the person’s system but the level was low enough that the drug likely did not have an effect. This could be described as a person who takes a depressant drug as a sleep aid. The next day, if he or she is involved in an accident, there might be a small amount of the drug remaining in the body. The toxicologist would find it, quantitate the drug and find that indeed, the level was so low that the person was most likely not affected by the drug. The trier of fact could then take that into consider- ation during deliberations and possibly find that the accident was just an accident rather than an accident caused by an impaired person.

Mike Derer/Associated Press Samples at forensic toxicology laboratories are run through various tests for analysis, including immunoassay tests. Do you think individual states should be allowed to determine what BAC level implies impairment?

Section 5.5Toxicology Laboratory Testing

A therapeutic level of drug means the drug is in the person’s system and is at a level that the drug’s effects are present. Again, the toxicologist cannot say the person was impaired, but he or she can say that the drug was present at such a level that its effects could have been a factor in a case. An example of this involves a person who takes a depressant drug and tries to drive immediately after consumption; when the drug is distributed in the system, the person dozes off in the car and is involved in an accident. The toxicologist quantitates the drug and finds it to be in the therapeutic range. The toxicologist relays this to the court and describes how the effects of the drug present themselves. The toxicologist says that the levels of this depres- sant could cause drowsiness, decreased attention, slowed reflexes, and relaxation. The police officer would need to fill in the details of how the suspect was acting at the scene. If what the officer reveals and what the toxicologist describes are similar, the trier of fact could find that the person was impaired and reach a verdict reflective of these facts.

The third level that a toxicologist looks at is the lethal level, to see if there is enough drug in the system to kill the individual. This usually involves postmortem toxicology. For example, a body is found with pill vials nearby, or a body is found with a syringe and packet containing illegal drugs. In either case, the toxicologist identifies the drug in the body and quantitates to find if the level present was at or above the lethal level. If so, it would be reported and would help the coroner or medical examiner reach a conclusion about the cause and manner of death in the case. Toxicology testing takes time. That is why you may have noticed that in high-profile cases, the medical examiner or coroner waits for the toxicology results to come back before making statements about the cause of death. One must note that not everyone will die just because there is a high concentration of drug in their system. Many addicts can survive a level that would be lethal to a novice user because they have developed tolerance to the drug. This does not indicate lack of impairment; it only indicates that they can take higher doses of drugs and not die.

Drugs We have discussed the entire process from first observation by the officer through analysis by the toxicologist. However, what does this testing mean for the law enforcement officer, victim, and suspect? Through analysis, the toxicologist can identify drugs and ethanol in the provided samples. A report of these findings is sent to the law enforcement agency that submitted the case. If no drugs or ethanol are found, the case may be dismissed. If drugs are found, the suspect may be charged with DUID. If the drugs found fall under the abused drugs list, then any per se law goes into effect. In other words, the mere presence of drugs in the suspect’s samples indicates impairment. If prescription drugs are found and quantitated, the toxicolo- gist will testify at trial as to what the level means in normal people. This seems very simple; however, there are other toxicological issues that can come into play. Remember that drugs

Think About It

The per se law states that the presence of an abused drug, no matter the quantity, renders the person impaired. Do you think this is a fair law? Why or why not?

Section 5.5Toxicology Laboratory Testing

are metabolized in the body. These metabolites may be inactive but may remain in the blood or urine longer than the active parent drug.

Let’s take cocaine as an example. Remember, cocaine is a controlled substance. It is a stimulant and can cause a decrease in judgment and inhibitions that can lead to accidents or improper behavior. Cocaine is metabolized to benzoylecgonine, an inactive compound that remains in the body for a while after the cocaine has disappeared. If the analyst only finds the metabo- lite, does this mean the person was not impaired? The defense will certainly try to present this point. The analyst must remain unbiased in the case. The analyst can state that benzoy- lecgonine results when cocaine is taken but will not be able to say for certain that there was cocaine in the system at the time of the traffic stop. The evidence provided by the officers on the scene will be used to convince a judge or jury that the person was under the effect of the drug when stopped.

Ethanol Ethanol is much easier to work with than illicit drugs. All states have a level of ethanol at or above which the suspect is deemed to be impaired. Most states use the level of 0.080 g/dl. (Remember that a gram is around ¹∕₂₈ oz.; a “dl” or deciliter is ¹∕₁₀ of a liter, or a little less than ½ cup.) In layman’s terms, this means that in every 100 ml (one deciliter) of blood, there are 0.080 grams or 80 milligrams of ethanol. The amount of alcoholic beverage it takes to get there is dependent on the weight and gender of the individual. There are several charts avail- able on the Internet that provide rough estimates of alcohol concentrations based on weight, gender, and the number of drinks consumed. An example of one of these charts is shown in Figure 5.1. In these charts one must remember that a “drink” is usually defined according to Table 5.2.

Figure 5.1: Blood alcohol concentration

As shown in the chart, having one to two drinks can significantly change a person’s BAC, depending on his or her weight and the amount of time between each drink. Do you agree that having a BAC of 0.080 g/dl (or .08%) should result in a DUI? Why or why not?

“Actions Resulting in Loss of License,” by State of California Department of Motor Vehicles, n.d. Retrieved from https://www.dmv .ca.gov/portal/wcm/connect/7ed001aa-cc59-4ba4-897c-c0f7aac4d7c2/chart_10_bac_chart.pdf?MOD=AJPERES&CVID=

90 to 109 lbs.

Time from 1st

drink

1 hr

1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8

2 hrs

3 hrs

4 hrs

110 to 129 lbs. 130 to 149 lbs. 150 to 169 lbs.

Total Drinks Total Drinks Total Drinks Total Drinks

170 to 189 lbs.

1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8

190 to 209 lbs.

210 lbs. and up

Total Drinks Total Drinks Total Drinks

Key

.01–.04% May be DUI De�nitely unlawful if under 21 years old

.05%–.07% Likely DUI De�nitely unlawful if under 21 years old

.08% and up De�nitely DUI

Section 5.5Toxicology Laboratory Testing

Table 5.2: The amount of alcohol in different drinks

Drink Amount Alcohol concentration Alcohol present

Normal American beer 12 ounces 4% or 8 proof 0.48 ounces

Wine 6 ounces 8% or 16 proof 0.48 ounces

Mixed drink 1.25 ounces 40% or 80 proof 0.48 ounces

Mixed drink 1 ounce 50% or 100 proof 0.48 ounces

As you can see, the “normal” drink has approximately ½ ounce of pure alcohol in it. However, when people drink, they often do not have a normal drink. How many times have you seen offerings at bars of “tall beers” that contain 16 or 20 ounces of beer? The same can happen with mixed drinks containing higher proof liquors. People may not actually know how much alcohol they are putting into their system.

People also do not respond in the same way to a particular BAC level. One person may appear normal at a 0.080 g/dl level, but another person may be obviously impaired.

This difference in response is called individual variation and can be due to genetics, previous alcohol use, or a number of other factors. One thing to remember is that even when people look like they are sober, alcohol is depressing inhibitions and judgment. This depression is a major cause of accidents. Drivers get into dangerous situations and do not use good judg- ment. At higher alcohol levels, the impairment of reflexes and visual disturbances contribute. If enough alcohol is consumed, a person will pass out, can go into a coma, and can die. Death can happen due to aspiration, in which a person who has passed out and is lying faceup can vomit and then inhale the vomit into the lungs. Death can also happen due to excessively high alcohol concentrations. The average person dies at a level of 0.450 g/dl.

Alcohol in the Body When a person begins drinking, the alcohol is absorbed into the bloodstream and distributed through the body. This is the absorption phase. Once a person stops consuming alcohol, he or she will reach a peak blood alcohol level and then the level will begin to decrease. The time of this peak is dependent on food intake. If a person drinks on an empty stomach, the peak is reached in 15 to 30 minutes. If a person has been eating, the time to peak absorp- tion can be from 60 to 90 minutes (Baselt, 2011). Regardless, once the peak alcohol level has been reached, metabolism takes over, and the level begins to decrease. The average meta- bolic rate for alcohol is 0.015 g/dl/hr. This means that individuals who are at a 0.080 g/dl at

Think About It

The bars that offer large beers often offer craft beers as well. Some of these can con- tain up to 14% alcohol, compared to the normal 4%. What added danger does this present to the customer?

Section 5.6Drug-Facilitated Sexual Assault

their peak will be approximately 0.065 g/dl 1 hour later. This decrease continues until the alcohol is gone. This is a slight oversimplification, since metabolism is going on at the same time as absorption, but levels rise as long as intake of alcohol exceeds metabolism, and levels decrease when metabolism is greater than intake. Hence, 0.015 g/dl/hr is an average (Baselt, 2011). Some people metabolize more slowly and some more rapidly, depending on health, genetics, and other factors.

Alcohol is metabolized in the liver. There are two enzymes involved in the process. The first, alcohol dehydrogenase, converts ethanol to acetaldehyde. The second, aldehyde dehydroge- nase, converts the acetaldehyde to acetic acid. The first enzyme appears to operate as long as alcohol is present. The second enzyme appears to have various genetically controlled forms that operate differently. Depending on the form a person has inherited from his or her parents, the acetaldehyde metabolizes at different rates. Some metabolize the acetaldehyde efficiently, while others metabolize more slowly, allowing acetaldehyde to build up in their system. Since this is genetic, individuals may not know how they will metabolize until they consume ethanol. If they have a slow-functioning aldehyde dehydrogenase enzyme, they will build up acetaldehyde in their system and experience the associated flushing and nausea.

Calculations There are some calculations that the toxicologist can perform regarding alcohol. As men- tioned previously, if serum is used to determine alcohol concentration, the level must be con- verted to a whole BAC, because that is the way the impairment level is written into the law. Another calculation can assist in determining the approximate BAC at the time of an incident, even when the blood or Breathalyzer test is not completed until hours later. Remember that on average, a person eliminates approximately 0.015 g/dl of ethanol per hour. If the toxicolo- gist knows an alcohol level and the time difference between the test and an incident, such as an accident or traffic stop, 0.015 g/dl can be multiplied by the time difference in hours, calculating the amount of ethanol eliminated. That amount can be added to the level from the test; the result is the approximate level at the time of the incident. Finally, the toxicologist can estimate the amount of ethanol in a person’s system and convert it to an approximate number of drinks in the individual’s system. This can be done if the toxicologist is provided with the person’s weight, gender, BAC, and what the person was drinking. This becomes an issue when the driver states that he or she only had a couple of drinks, but his or her BAC is exceedingly high. This can be the result when people forget how much they drank or are not drinking “normal” drinks.

While the bulk of the forensic toxicologist’s duties will be related to human performance and finding drugs or alcohol in submitted samples, there are other aspects to the analysis per- formed by these scientists. Drugs can be delivered to victims unknowingly. Some of these drugs are given by a suspect to render a victim unconscious so they can be sexually violated. This is often known as drug-facilitated sexual assault.

5.6 Drug-Facilitated Sexual Assault Another analysis completed by toxicologists involves the crime of drug-facilitated sexual assault (DFSA). Giving a person a drug for the purposes of rendering him or her incapable of giving informed consent to sex can result in charges over and above rape at trial. Most of

Section 5.6Drug-Facilitated Sexual Assault

the drugs used are in the depressant category, and most of the time alcohol is also involved. When a victim of rape goes to a hospital, the primary concern is the health and well-being of the individual. Samples specifically related to the assault are collected, but occasionally drugs will not be considered.

As was mentioned briefly in Chapter 1, some nurses receive special training to deal with sexual assault. These are called sexual assault nurse examiners (SANEs). These specially trained nurses have added knowledge related to sample collection, preservation of the sample, main- tenance of chain of custody, and testimony in court. In areas such as Chicago and the rest of the state of Illinois, where SANE nurses have been a part of evidence collection in sexual assault cases, prosecution rates have increased because of their expertise (Illinois Attorney General, 2010). Part of their training includes determining whether drugs have played a part in the crime.

If drugs may be involved, a urine sample is necessary. The urine can be tested for the presence of drugs and alcohol, but no lev- els will be determined. Because some of the drugs used are very potent and have short half-lives in the body, such as alpra- zolam, the sample must be collected as soon as possible. Additionally, the toxicol- ogist must be made aware of the nature of the crime, since some drugs, such as GHB, need specialized testing. Some testing may be completed at a hospital, but remember that although hospitals can determine that a depressant is present, they cannot directly identify the drug. For court purposes, the identification of the drug is essential, and since many hospitals do not perform confirmatory testing, the samples must be sent outside to testing laboratories.

One of the drugs that received a great deal of press as a date rape drug was Rohypnol, the standard dosage form of flunitrazepam. This drug was known on the street as “roofies.” Fluni- trazepam is a potent benzodiazepine that causes sedation, muscle relaxation, loss of anxiety, and loss of inhibition. This drug is also known to cause amnesia in the victim. It accomplishes this so well that another of the street names for Rohypnol is the “forget me drug.” Because of its misuse, the manufacturer has added a dye to the formulation to make it obvious that a drug was added to a potential victim’s drink. Rohypnol is given in 2 mg dosage forms, so it is fairly potent; however, it has a half-life of about 20 hours. This means it can be detected in the urine for about 3 days. Rohypnol also has a metabolite that can be detected in the urine, aiding in analysis. This drug has not been approved for use in the United States by the FDA, so it has always been illegal and unavailable unless purchased outside the country and brought in surreptitiously.

Other benzodiazepines have been used in DFSA. Benzodiazepines are often used because, as mentioned in Chapter 4, benzodiazepines react in a synergistic manner with alcohol. That

World History Archive/Superstock Although Rohypnol has never been approved as a legal drug in the United States, in other parts of the world, it is available by prescription to treat insomnia.

Section 5.6Drug-Facilitated Sexual Assault

means the victim given a benzodiazepine-laced beer acts as though he or she had three to five beers, or had taken three to five doses of benzodiazepine, instead of just two. The benzodiaz- epines are found in the urine through normal testing in the toxicology laboratory. The major concern is passage of time between dosing and sample collection. The more time that passes, the less likely the toxicologist is to find the drug.

Other drugs require more specialized testing. GHB has an extremely short half-life, between 20 and 60 minutes (Baselt, 2011). This means that 4 hours after dosing, over 93% of the GHB is metabolized. GHB requires specialized analytical testing not normally pursued unless specifically requested. Additionally, GHB is a compound found naturally in the body. Though it is at a very low level, its presence poses a serious problem for the prosecution of a case. If DFSA is suspected, and the victim arrived at the hospital hours after the incident and urinated before going to the hospital, analysis cannot be completed for GHB, as nearly all evidence has been eliminated. If GHB is found in this case but is detected at the level normally found in humans, the toxicologist could not say the victim was dosed with the drug. What has been found may just be the naturally occurring level in the person. The toxicologist can only state that GHB was used in DFSA when the level is higher than that seen in endogenous levels.

One might ask, if a case is submitted to the toxicology laboratory and is listed as DFSA, does the toxicologist only look for drugs associated with that crime? The answer is no. The toxi- cologist will still examine the sample for all of the drugs as standard procedure but will do additional testing for date rape drugs. It is important to find all drugs present in the urine. This can make some victims uncomfortable, especially if they have engaged in recreational drug use, such as smoking cannabis. Care must be taken to make victims comfortable and let them know that the recreational use is not of concern to law enforcement.

The toxicologist will not be able to tell the impairment level of the victim during the assault. Remember, urine is not quantitated for drug levels, since urine levels cannot be related to impairment levels; if any information about drug levels is needed, blood must be tested quan- titatively. The toxicologist may be able to provide information on the effect of drugs alone and in combination with other drugs. However, there will most likely not be any officer who can testify about impairment, since the victim will most likely not get to the hospital for hours after the crime takes place. This will make any determination of behavior at the time of the crime nearly impossible. The importance of the toxicologist’s testimony is that the drug was found and the exact identity of it was determined. After that, the drug must be tied to the sus- pect, and it must be shown that the victim was not taking the drug of his or her own accord. The toxicologist will relay the complete findings of the analysis. If recreational drugs or alco- hol were found in analysis, this will be disclosed. The toxicologist will not be able to say how the drugs got into the victim, only that they were present.

Think About It

Since the SANE program is helping in the judicial process for DFSA cases, do you think that other medical personnel could receive training to assist in other types of cases? What types of cases do you think would benefit?

Section 5.7Forensic Urine Drug Testing

5.7 Forensic Urine Drug Testing The final topic for discussion in this chapter is forensic urine drug testing (FUDT). In today’s employment climate, most people have probably been drug tested. FUDT started as employ- ment drug screens. It has spread into the law enforcement world through testing of urine of probationers and parolees, as well as testing of athletes for drugs of abuse and performance enhancement. It has even spread into the horse racing industry, where winners have their urine tested for proscribed drugs. For our purposes, we will stick to human testing for law enforcement, though this closely mirrors the screening completed on applicants for jobs and that used when employees are randomly drug tested in the workplace.

Urine drug screens normally look for what have been referred to as the NIDA-5, the five classes of abused drugs checked for in laboratories as determined by the National Institute on Drug Abuse (NIDA). These are amphetamines, opiates, phencyclidine, cocaine, and can- nabis. These were historically the drugs and drug classes most abused. Testing begins on samples using immunoassays. This test is the same screening test used in the forensic and medical industries. At first, this was the only test done for workplace testing. Unfortunately, many false positive results were seen. For example, people who had taken cough syrup with phenylpropanolamine were listed as positive for amphetamines. The conclusive identifica- tion of drugs eliminated the false positive tests in the amphetamine class. Another problem was seen with opiates. Reports appeared of people who had submitted urine samples that tested positive for opiates after they had just eaten something with poppy seeds. Research was completed, and it was found that if a person consumed enough poppy seeds and gave a urine sample within several hours of that consumption, it was possible to trigger a positive test. Guidelines were again set up so that confirmation would take into account the possibility of poppy seed consumption. Today this is not really a problem.

While false positives were an issue in the past, safeguards have been instituted that make false negative results unlikely. A false negative would result when testing indicated there was no drug present when in fact there was. Many people have tried to alter their urine samples so that the drug that might be present would be missed in analysis. These problems have been addressed, as well.

The NIDA was the original agency that licensed testing facilities. It also instituted the guide- lines for acceptable testing to avoid false negatives and false positives from the laboratories doing the FUDT. These included the confirmation of the identity of drugs found in samples. They also took into account the fact that people might have passed through rooms where drug use was ongoing but did not participate. These people might have had passive contact and been exposed to drugs without using them and could have trace amounts in their system through passive inhalation. Today the FUDT laboratories use immunoassay testing to find if drugs might be present, and the drugs are then confirmed using gas chromatography/mass spectroscopy (GC-MS). The immunoassay screening tests have cutoff levels for the various classes of drugs to eliminate the possibility of positive results based on passive inhalation. What this means is that each drug class has a level greater than zero (no drug present), which would still be considered negative. If the immunoassay tests indicate levels less than the cut- off value, the sample is considered negative for drugs, and testing is complete. If the sample gives a reading above the cutoff level, it is considered positive, and the sample is isolated for confirmatory testing with GC-MS. This final test will tell which drug is present in the sample. If, for instance, the drug found is phenylpropanolamine, which is a common component in

Section 5.7Forensic Urine Drug Testing

cold medications, the result will still remain negative. If the drug is methamphetamine, the report will read as positive for that drug.

There are people being tested who have become aware of the procedures being used and tried to beat the test through adulteration, or the intentional addition of some chemical for the purposes of interfering with the testing processes, of their urine samples. The goal of adulteration is to create a false negative test result—in other words, affecting the testing in some way so that a person who has used drugs will not get caught. Since the testing only worked with urine at normal levels of acidity and alkalinity in people, those who were afraid they might give a positive test result would try to alter the pH (acidity) of their urine. Some would drink vinegar to make it more acidic. Others would add bleach to their samples to make it alkaline or basic. Other tricks were used to “beat the test” as well. Some people sub- stituted drug-free urine for their own urine. They would get a sample of urine from a friend who did not use drugs, conceal it, try to carry it into the testing facility, and then place it in the sampling cup instead of their own urine. In some facilities this worked for a while. How- ever, the industry was forced to become more sophisticated in its methods of testing. Now, the facilities have methods of checking the temperature of the urine. Urine carried outside the body is too cool and will no longer be accepted. Another method of trying to beat the test was to take herbs and drink large amounts of water. This did not eliminate all of the drug but lowered its concentration so testing indicated levels below the cutoff, resulting in a nega- tive report. Again, a method to detect this was found. The body creates a compound called creatinine that is excreted in the urine. In healthy individuals, there is an average concen- tration range for this compound. Drinking large amounts of water dilutes not only the drug concentration but also the creatinine concentration. This serves as an indicator that diluting and flushing is taking place.

If it seems like a great deal of time and effort has gone into detecting people trying to beat the test, there is a reason. Some states have passed legislation mandating that FUDT laboratories report possible adulteration of urine samples for the purposes of trying to beat the test. If, for instance, a collector noticed the urine had a very low temperature when collected, it would be stated on the report. The same would happen if the urine had a very high or low pH, or if the creatinine level was low and far outside the normal range. Employers have learned not to look at just the results but also the condition of the urine sample, noting indicators that someone has tried to beat the system. While the states do not have a vested interest in the information reported by the laboratories, the employers gain information about the people they are get- ting tested.

Forensic toxicology laboratories follow many of the same guidelines for analysis in urine samples being tested. Many of the cases that require such testing are probation cases. Many parolees are randomly chosen to give urine samples to prove they are not using drugs. When this sample comes into a lab, under seal and with complete chain of custody, the analyst will run preliminary testing for the five classes of abused drugs. If the preliminary testing is nega- tive, the case will be closed and reported as negative. If drugs are indicated in the preliminary test, then conclusive testing will be completed to identify the drugs. The report will reflect what drugs were identified.

In spite of the protocols that laboratories have in place, one aspect of testing urine is difficult to catch. In casual users, the drugs of abuse that are being tested for are undetectable in the urine after 72 to 96 hours have passed, and with some drugs, even less time is needed. This

Conclusion

means that if someone is prepared for the test, he or she can abstain from drug use for 3 or 4 days and will test as drug free. A test developed in the past decade has expanded the drug detection limits for forensic and employment testing. Techniques have been developed that allow testing of hair for the presence of drugs. Since nutrients to the root of the hair are deliv- ered by the blood, drugs in the blood can also be deposited in the hair. After the drugs are deposited, they will not leave, but are instead trapped until that section of hair is cut off. This allows the testing laboratory to have a sample with a longer record of drug use.

Testing facilities have had to develop techniques that can provide information that the drug came from inside the hair and was not deposited on the outside of the hair, as would happen with passive contact. Once these techniques were validated, testing could give a record of drug use much longer than any urine sample. Head hair grows on average about 1 cm, or about ½ inch, per month. A hair sample is collected by cutting hair off next to the scalp in an amount about the diameter of a pencil. This hair sample can be sectioned into ½-inch pieces. Each section can be tested for drugs. Typically, only the last 3 inches, or about 6 months of growth, will be tested. This will tell the drug history of the individual for that period of time. Of course, people have again tried to beat the test by shaving their heads, but a drug can be found in any hair. One aspect to hair testing should be considered with care. This testing can- not tell exactly when a person used drugs; it only shows that a person took drugs during a month of time as shown in a certain section of hair. Additionally, there is nothing in this test that indicates impairment due to the drugs. This testing is much more expensive than urine testing, so if a company uses this type of testing, it is serious about drugs in the workplace.

Conclusion Forensic toxicology is used in a wide variety of casework in forensic science. The testing can determine if a person had drugs in his or her system, provide a blood alcohol level that can be used in the determination of DUI cases, and tell if a person died of drug overdose or was poisoned by a toxic compound. Testing procedures are extensively validated, and controls are run on a daily basis to confirm the functioning of the instruments in the toxicology labora- tory. The toxicologist has the tools necessary to assist the case in the identification of myriad compounds for forensic use and has the knowledge to assist the courts in the determina- tion of what the effects could possibly have been. As the drugs become more potent and new designer drugs come on the market, the challenges facing the toxicologist will keep the excit- ing field of forensic science continuously growing.

Key Ideas

• Toxicology is the study of the effects of poisons and toxins in the body. Forensic toxi- cology applies that information to the courts.

Think About It

FUDT is also used in many other ways. Where do you think this testing is used outside of forensics?

Conclusion

• Forensic toxicology can be used in poisonings and human performance cases. The majority of cases forensic toxicologists deal with are DUI and DUID cases.

• Several types of poisons that can be encountered in forensic toxicology cases include heavy metals, pesticides, carbon monoxide and other gases, drugs, and alcohol.

• Chain of custody is important in forensic toxicology cases to make sure the evidence is admissible in court.

• Qualitative testing tells what is in a sample, while quantitative testing tells how much of the substance is present in a sample.

• Drug recognition experts are police officers trained to assess suspects who may be under the influence of drugs. Through interviews, testing through the SFST, and gen- eral observation of the suspect, they may be able to ascertain if the suspect is under the influence of depressants, stimulants, hallucinogens, phencyclidine, opiates and narcotics, inhalants, or cannabis.

• Preliminary or screening tests tell what class or category of drug may be in a sample; confirmatory tests tell with certainty what drugs are present and the quantity.

• Toxicology testing is rigorous and involves the use of positive and negative controls to make sure all testing is functioning properly and quantitative controls to make sure all quantitative results are accurate.

• Drugs generally are prosecuted under per se laws, which means that any amount of drug in the system indicates impairment, while ethanol relies on certain levels in the blood or breath to determine impairment by statutory definition.

• Drug-facilitated sexual assault occurs when a person tries to incapacitate or render a victim unable to make informed decisions about engaging in sex through the use of drugs.

• Forensic urine drug testing has become highly controlled to make sure that correct results from testing are generated by the testing laboratory and also that adultera- tion of samples by the person being tested is detected and reported.

• Hair testing is now being used and can increase the detection time of drugs in people. Care must be taken with the results to make sure no misrepresentation of the findings occurs.

Critical-Thinking Questions 1. Knowing what you know about ethanol and BAC, how would you explain in court

what it means to be “driving under the influence,” if you were a toxicologist testifying in a court case about someone driving under the influence of alcohol and hitting a pedestrian?

2. Arsenic has been used in poisonings because it could be misdiagnosed as a disease. Do you think that a clever poisoner could get away with murder today if he or she chose the right poison?

3. The organophosphate pesticides have been seen in accidental poisonings. What other examples can you think of that use these compounds? What steps do you think should be taken to prevent accidental poisonings?

4. DRE programs are becoming more prominent in officer training. Do you think this program should be a requirement to become a police officer? Why or why not?

5. If a person is found dead with many pill bottles around him or her, does this neces- sarily mean the person died of a drug overdose? Explain your reasoning.

6. Do you think the DRE will ever take the place of a toxicologist in court? Why or why not?

Conclusion

7. A person fails his or her SFST and has a fruity odor on the breath. Could this be any- thing other than alcohol intoxication? If so, what?

8. There is a lot of time spent analyzing controls in toxicology. Why do you think all of these controls are necessary?

9. If the average person can die at a 0.450 g/dl level of ethanol, why are some samples seen that have higher levels in living people?

10. The SANE nurses can help get good evidence for testing. How is this affected if the victim waits 2 or 3 days before going to the hospital after an assault?

11. If a person can be shown to have altered his or her urine to try to get a negative FUDT result, what do you think should be done?

Key Terms acute Immediate, or seen very soon after; acute tolerance, for example, is seen within hours of exposure to a compound.

adulteration The act of adding a chemical to a sample for the purposes of interfer- ing with testing by a hospital or forensic laboratory.

blood draw A sample of blood taken in order to test for medical or forensic purposes.

breathalyzer test A device used to deter- mine the breath alcohol concentration (BrAC) of a suspect.

carbon monoxide (CO) A highly toxic gas, usually produced by combustion of hydro- carbon fuels.

chronic Something that takes place after a longer period of time; for example, chronic dosing means giving a drug for a long period of time, as opposed to a single dose.

confirmatory testing Used to conclusively identify the particular drug or drugs present after it has been determined that a particu- lar class of drug might be present.

date rape drug A drug that is used to render a victim unconscious or incapable of saying yes or no to sexual intercourse.

drug-facilitated sexual assault (DFSA) The process by which a person tries to incapacitate or render a victim unable to make informed decisions about engaging in sex through the use of drugs.

drug recognition expert (DRE) A police officer trained to evaluate suspects and determine if drugs may be involved in their behavior.

false negative A sample does contain a drug, but this drug is not found during testing.

false positive A sample does not contain a drug, but testing indicates the presence of that drug.

forensic urine drug testing (FUDT) Test- ing that can be used to determine drug use in individuals through the use of a urine sample, often for parole cases and employ- ment screens. Testing is generally for opi- ates, amphetamines, cannabis, phencycli- dine, and cocaine.

gases Substances that are vapors naturally or at low temperatures, including CO and inhalants.

headspace gas chromatography A form of gas chromatography that uses as the injected sample air collected from above a liquid that contains the compound of inter- est, such as air taken from a sealed vessel that contained blood suspected of having alcohol in it.

Conclusion

heavy metals Elements that are toxic when ingested, such as mercury, lead, arsenic, and thallium.

human performance The ability of a person to complete tasks under various conditions. In toxicology, this usually refers to impairment caused by ingestion of drugs or alcohol.

immunoassay tests A class of tests that relies on a reaction between antigens and antibodies to produce a result.

internal standard A compound that is not likely to be found in a sample, which can be added during analysis to help standardize results for quantitation and identification of a drug.

metabolism The process by which the body breaks down drugs and other materi- als to enable their elimination from the body in the urine or feces.

metabolite The breakdown product of a drug once it has been metabolized by the body.

negative control A standard sample that does not contain a drug and is used by the analyst to make sure that the test being used is working and will show a negative result when the sample does not contain the drug being tested for.

NIDA-5 The original five classes of drugs of abuse that were screened for in urine drug testing: amphetamines, cocaine, phencycli- dine, cannabinoids, and opiates.

pesticides Compounds used to kill pests, such as insects, rats, mice, or other similar animals.

poison Any substance capable of causing death, illness, or harm when taken into the body.

poisonings The act of ingesting a toxic substance, which can cause bodily harm or death. This can be accidental or intentional.

positive control A standard sample that does contain a drug and is used by the analyst to make sure that the test being used is working and will show a positive result when the sample does contain the drug being tested for.

postmortem redistribution The pro- cess by which, after death, some drugs can move from a tissue into the blood or diffuse from the blood into a tissue. This can cause unusual values during the determination of the amount of drug in the tissues or blood. In order to determine if this has happened, many different samples may be taken and compared.

qualitative testing Testing that is used to determine what compounds are in a sample.

quantitative controls A series of dilu- tions of the compound of interest, which can be tested to form a chart that assists in determining the amount of compound in a sample.

quantitative testing Testing that is used to determine the amount of a compound in a sample.

serum The fluid remaining when blood is allowed to clot and the clot is then removed.

sexual assault nurse examiners (SANEs) Nurses specially trained to help collect and preserve evidence in sexual assault cases.

standardized field sobriety test (SFSTs) Testing given to a suspect thought to be under the influence of drugs or alco- hol, consisting of the walk and turn, finger to nose, and one-leg stand tests.

Conclusion

testing of hair In forensic toxicology, deter- mining the presence of drugs, drug metabo- lites, or toxins in a person’s hair.

toxicology The study of poisons and toxins in the body.

urine sample A specimen of urine known to have come from a particular person.

Web Resources The NIDA website: http://www.drugabuse.gov

A sample BAC calculator: http://witrafficsafety.org/bac-calculator/

Audio news story on the history of toxicology: https://www.npr.org/templates/story/story.php?storyId=124358332