1. Eyewitness Testimony

2. What is Testimonial Evidence?
Testimonial evidence includes oral or written statements given to police as well as testimony in court by people who witnessed an event.
Eyewitness accounts can be a useful tool in helping investigators with analyzing a crime scene, but are not viewed to be highly reliable. In addition, eyewitness identifications (right or wrong) can have a big influence on the outcome of an investigation or trial.
People are likely to view the same scene in different ways depending on their positions, line of sight, familiarity with the area, and other factors that can interfere with a person’s ability to remember details.
Forensic Science: Fundamentals & Investigations, Chapter 1

3. The Innocence Project
Barry C. Scheck and Peter J. Neufeld at the Benjamin N. Cardozo School of Law, starting in 1992, use DNA to examine post-conviction cases.
The project has found that up to 87% of the wrongful convictions they discovered were due to faulty eyewitness identifications.

4. What factors affect a person’s memory and their ability to identify a suspect?
Witness Factors
Crime Scene and Suspect Factors
Forensic Science: Fundamentals & Investigations, Chapter 1

5. Witness Factors Age Race Use of Drugs or alcohol
The cross race effect (CRE) is a phenomenon in which people are better at recognizing faces of their own race rather than those of other races.
Use of Drugs or alcohol

6. Witness Factors Their emotional states at the time of the incident
Whether they were alone, part of a group, or whether others were in the area.
A person’s memory of an event can be influenced by other witnesses, investigators, and/or the media.
What type of and how much activity was going on around them.
Forensic Science: Fundamentals & Investigations, Chapter 1

7. Crime Scene and Suspect Factors
Traumatic events can affect an eyewitnesses recall of the event.
For example: a witness confronted with a weapon tends to focus on the weapon rather than the perpetrator’s face.
Time of observation of the crime scene
Someone who is able to focus on a perpetrator’s face for a minute or longer will tend to have a more accurate memory than someone who saw the person for only a few seconds.
Forensic Science: Fundamentals & Investigations, Chapter 1

8. Crime Scene and Suspect Factors
The suspects physical appearance
Studies have shown that faces that are either highly attractive, highly unattractive, or distinctive are more likely to be accurately recognized.
Simple disguises, such as hats or sunglasses, can interfere with accurate identification of a suspect.
Body piercings and tattoos increase the likelihood of an accurate identification.
Forensic Science: Fundamentals & Investigations, Chapter 1

9. Crime Scene and Suspect Factors
The time of day
The person’s view of the scene
Familiarity with the area in which the crime took place.
Forensic Science: Fundamentals & Investigations, Chapter 1

10. Eyewitness Accounts
Reports from individuals about crime-scene events often vary.
Observations depend on the level of interest, stress, concentration, and the amount and kind of distractions present.
Prejudices, personal beliefs, motives, and any lapse in time since the occurrence can also have an effect.