SEC430 Evidence Tracking

Evidence Tracking

Evidence Tracking

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Evidence Tracking

Evidence is essential to solving any case and proving the guilt of an offender in a court of law. Once a crime has been reported the first step of the responding officer is to secure the crime scene to ensure it is properly preserved until forensic investigators can arrive on the scene. The evidence collection process begins with thoroughly documenting the crime scene. The process begins with a walk through of the crime scene in order to identify potential evidence and to develop an idea of what occurred at the crime scene. Once the evidence has been identified the evidence collection process will begin with collecting evidence that is fragile or easily damaged or destroyed.

In the rape scenario DNA evidence is crucial to proving a crime occurred and showing the guilt of the offender. Rape cases are hard to prosecute and require physical evidence to prove the act of rape even occurred. In a majority of cases it is the word of the victim against the word of the perpetrator. DNA evidence can provide conclusive evidence that a sexual assault occurred and point to the guilty offender. In the rape scenario evidence that was located and will need to be collected is the semen on the comforter and the tissue located in the trash can. This evidence can contain valuable DNA that points directly to the offender. The semen and the tissue can contain the DNA profile of the offender and the tissue.

The evidence collection process begins first by identifying the evidence in a walk through and then properly documenting the evidence. Documenting the evidence is an essential step in the collection process. This begins with photographing the evidence where it sits in order to show the court where the evidence was located and in what condition. Once the evidence has been photographed it must be collected using uniform collection standards. The comforter that was located contained a semen stain that must be collected in order to develop DNA on the criminal suspect. Most items of evidence will be collected in paper containers such as packets, envelopes, and bags and liquid items can be transported in non-breakable, leak proof containers (Schiro, 2006).

When collecting DNA from the comforter the forensic technician will mark the wet stain with a permanent marker in order to make it easier to locate during the DNA analysis. The technician will then wait for the comforter to air dry before placing it in a clean package and properly sealing and documenting for transportation. The second piece of evidence that was located at the crime scene was a tissue in a waste paper basket. The tissue will need to be collected using a pair of tweezers or using a pair of gloves and then be placed in a plastic container. The plastic container will need to be sealed and then properly documented for transportation.

Documentation does not include just sketching and photographing the evidence located at the crime scene but also includes detailing every step of the evidence collection process, transportation, and steps taken in the analysis of the evidence at the lab. Documenting includes ensuring the person that collect the evidence labels the document with their name, date, time, number, and the steps that were taken in the collection process. When the evidence is transported these steps also need to be documented. The person transporting the evidence needs to document time and date evidence was transported and by whom. Once the evidence reaches the lab for analysis each step in the process must also be carefully documented.

Documenting every step in the evidence collection, transportation, and analysis process is known as the chain of the custody. The chain of custody is defined as the witnessed, written record of all of the individuals who maintained unbroken control over the items of evidence (Byrd, 2009). The chain of custody shows the court where the evidence was located and shows exactly what steps were taken to collect, transport, and analysis the evidence. The chain of evidence establishes proof for the court that shows who had contact with evidence, circumstances surrounding the collection of evidence, and any changes to the evidence.

Processing protocols are the uniform standards that must be followed when collecting evidence or processing a crime scene. These protocols as discussed previously include preserving the evidence, conducting a walk through, sketching the scene, photographing the scene, using standardized methods to collect evidence, document the evidence, and lastly transport the evidence to the forensic lab. The evidence located at the crime scene must be collected using processing protocols to protect the integrity of the evidence that is located.

Preserving DNA evidence is one of the most crucial steps that will be taken by forensic personnel. It falls to the responding police officers to quickly and properly secure a crime scene to ensure that evidence is not lost, damaged, or destroyed. DNA evidence can be extremely fragile and requires the roper processing controls and the preservation of the evidence. When processing DNA evidence, which has been transported to the forensic lab, it is essential to run negative controls and apply background controls through the entire process (Riley, 2005). This will ensure any containment is identified so the evidence does not be contaminated during the analysis process.

The potential DNA evidence on the tissue would be considered to be trace evidence because there is a possibility that minute amounts of DNA may be present on the evidence. Trace evidence is physical evidence fund in the smallest amounts and includes skin cells, fibers, and hair. The physical evidence located on the comforter is considered biological evidence or body fluids and can contain valuable DNA evidence that will point directly to a criminal suspect. DNA evidence can be located on the comforter through the use of ultra violet lights or chemicals.

Physical evidence is essential to the success of any criminal case. While many cases are solved with circumstantial evidence, physical evidence provides the court with more definitive evidence of the criminal defendant’s guilt. In order to ensure that physical evidence can be presented in court it must first be properly collected following uniform standards and it must be properly documented each step of the way. If evidence is not collected using uniform standards or is not properly documented there is no clear chain of custody. When the chain of custody has been broken the evidence will no longer be eligible for the court process.

If physical evidence is thrown out of court a guilty offender could go free. The chain of custody ensures that the court is aware of every step taken with the physical evidence and can prove the evidence being presented in court is the evidence that was located at the crime scene. The proof is established through the chain of custody and ensures the physical evidence is eligible for the court process. In order to prove the guilt of an offender there must be evidence pointing to a criminal offender that leaves no reasonable doubt in the minds of the jury. In the case of the rape crime scene the evidence that is collected will be crucial to identifying the suspect as well as proving their guilt.

References

Byrd, M. (2009). Proper Tagging and Labeling of Evidence for Later Identification. Retrieved

November 19, 2012 from http://www.crime-scene-investigator.net/tagging.html

Riley, D. (2005). DNA Testing: An Introduction For Non-Scientists An Illustrated Explanation.

Retrieved November 19, 2012 from http://www.scientific.org/tutorials/articles/riley/riley.html

Schiro, G. (2006). Collection and Preservation of Evidence. Retrieved November 19, 2012 from

http://www.crime-scene-investigator.net/evidenc3.html