CRJS406 DB2

Class Evidence

CRJS406-IP2

Name

Class

Date

Professor

Individual and Class Characteristics of Physical Evidence

Physical evidence is the pieces of evidence that are physically found and collected at the crime scene. Physical evidence is used to tie the criminal offender to the crime and prove the element of the crime. All physical evidence is class evidence and only becomes individual characteristic evidence when it is tied to a specific object or establish it uniqueness. Class characteristics are general characteristics of certain objects but because there are no specific characters to define individuality.

For example a shoe print outside of a crime scene is class evidence. Once it is lifted and identified to a specific shoe not a specific brand or model it will become individual evidence. The second examples of class characteristics evidence are fibers. There are millions of different fibers in the world. Until a fiber can be matched to a specific piece of material such as carpet, clothing, pillows, or furniture it has no individual characteristics but when it is matched to a specific rug, couch, or pillow it become individual characteristic evidence.

Physical evidence, such as fingerprints and DNA are only class evidence until they can be attached to a specific individual but are not class or individual characteristic evidence (NIJ, 2005). The last example of class evidence is tire impressions. When criminals flee a scene they may leave evidence behind from the tires on the car. Since every car in the world has tires it is consider class evidence even if the tire is a unique brand. Tires are matched based on their individual and unique tire tread patterns and wear.

Physical evidence with class characteristics can be used in court when it is tied to specific make, model or brand. Even if the shoe cannot be tied to one specific offender through unique or individuals characteristics it can be tied to the offender through circumstantial evidence. For example the court could provide a receipt showing the criminal defendant bout size 9 men’s Nike shoes but because the police never found the shoes they cannot be matched through unique tread and wear patterns to the criminal defendant it will remain class characteristic evidence.

Physical evidence can be considered a class characteristic at one crime scene and an individual characteristic at another. For example paint can be found at one crime scene and be considered class evidence because while the paint type was identified its location was not. At another crime scene the same paint chips could be matched to a car sitting in the drive way. Unless the class evidence can be tied to a specific object or individual it is not unique and not considered individual evidence.

In a second example tire treads at one crime scene can be matched to a specific vehicle while in others the tires can only be matched to a specific brand. Tire marks would also be considered class evidence unless they can be matched to a particular car, similar to foot tread patterns (Gross, 2010). Unless the exact set of tires can be found and matched to a vehicle driven or ridden in by the criminal defendant the evidence is only circumstantial despite the fact the evidence is actually physical. Class evidence is located at all crime scenes but does not become useful evidence unless it can be tied to the crime or crime scene.

Class evidence is used to develop more information on a criminal suspect leading to evidence that can directly tie the criminal. Without class evidence the police cannot develop individual characteristic evidence to use against a criminal defendant. If police can match tire impression evidence to the car of the criminal defendant it will establish the presence of the criminal defendant at the crime. Using the first example paint at the crime scene could be matched to paint at the place employment of the criminal defendant showing they had to be at the crime scene.

An investigator should consider regarding the use of class characteristics as evidence in court if the evidence is unique enough to be tied to the criminal defendant. For example if police establish the tires are Michelin this is not sufficient evidence to show they can be tied to the defendants even at a circumstantial level. This is different if the Michelin tire is a unique brand made by the company for only one year. While the evidence is still class evidence it is valid for showing the possibility the defendant and their car was at the crime scene.

The more unique the evidence the more likely it will be eligible as evidence to be used against a criminal offender. Even class evidence can be unique causing it to be good evidence against the criminal defendant. In order to use class characteristic evidence investigators must consider if the evidence is too broad or if it is specific enough to use against a specific criminal offender. If the class evidence is too broad a judge may rule it is not eligible or it cannot be definitely being tied to one defendant causing it to be too misleading. Class characteristics can only be used if the object can be ties to the defendant in some way.

In order to use individual characteristics evidence in court it must be tied to a specific object. Evidence cannot be introduced as individual evidence unless a specific object can be identified through unique characteristics. For example shoe impressions become unique based on the unique way people walk. If the tread pattern in the shoe impression left at the crime scene can be matched to a specific pair of shoes it can be used in a court of law to prove the guilt of a criminal offender.

References

Gross, J. & Fauss, M. (2010). Individual or Class Evidence. Retrieved October 19, 2013 from

http://www.theforensicteacher.com/Home_files/Evidence_type_lab.pdf

National Institute of Justice. (2005). Class and Individual Characteristics. Retrieved October 19,

2013 from http://www.nij.gov/training/firearms-training/module06/fir_m06_t04_05.htm