Brain Eyewitness Testimony

Eyewitness Testimony

PS 200

Eyewitness Testimony

Should the testimony of one eyewitness be enough to convict the accused of a crime? The one eyewitness holds your future in their hands, which could be freedom, prison, or even death. For example, in 1982 Ricardo Guerra was sentenced to death for the murder of a police officer (Death Penalty Info, 2001).The case against Mr. Guerra rested substantially on the testimony of 10-year-old boy whose father also was killed at the shootout (Death Penalty Info, 2001). A confident eyewitness should not be enough to convict someone of a crime; they may be confident, but does not mean they remember exactly everything that happened while they witnessed the crime. Furthermore, all the people that are involved in the crime and trial can sway the witness in several different ways. For example, law enforcement interrogations that are suggestive can lead witnesses to mistaken memories, even ones that are detailed and expressed with confidence (Loftus, 2003).

Perception is defined as our recognition and interpretation of sensory information including how we respond to the information (Matlin & Farmer, 2016). People can think of perception as a process where they take in sensory information from our environment and use that information in order to interact with our environment, furthermore, perception allows us to take the sensory information in and make it into something meaningful (Matlin & Farmer, 2016). Attention can be defined as a concentration of mental activity that allows you to take in a limited portion of the vast stream of information available from both your sensory world and your memory, meanwhile, the unintended items lose out, and they are not processed in detail (Matlin & Farmer, 2016). Working memory is the brief, intermediate memory for the limited amount of material that you are currently processing; part of working memory actively coordinates our ongoing mental activities (Matlin & Farmer, 2016). Long-term memory refers to the high capacity storage system that contains your memories throughout your lifetime (Matlin & Farmer, 2016).

Many factors can influence whether or not the eyewitness testimony is accurate. People may create memories that are consistent with their schemas, which consists of one’s general knowledge or expectation and it is distilled from their experiences with someone or something (Matlin & Farmer, 2016). Individuals use schemas to guide their ability to remember (Matlin & Farmer, 2016). As time passes, the individual will still remember the general picture of an event, although he or she may forget the information that is irrelevant for a particular schema (Matlin & Farmer, 2016).Perception and attention might influence the accuracy of the eyewitness memories in several different ways. Such as a phenomenon called own-ethnicity bias; which is when the eyewitness has trouble recognizing a person from another ethnic group or race (Matlin & Farmer, 2016). Faulty source monitoring, in other words, means individuals may believe they really witnessed something when it was actually suggested to them in a different situation (Matlin & Farmer, 2016). Here are several other factors that may influence the accuracy of the eyewitness:

Eyewitnesses make more mistakes if they saw a crime committed during a stressful circumstance, for instance, someone had a weapon.

Eyewitnesses make more errors when there is a long delay between the original event and the time of the testimony.

Eyewitnesses make more errors if the misinformation is plausible.

Eyewitnesses make more errors if there is social pressure, for example, when someone is pressuring them to give a specific answer.

Eyewitnesses make more errors if someone has provided positive feedback. In other words, praise them or just a simple “okay” can make the witness feel more certain about their accuracy.

(Matlin & Farmer, 2016).

6.Age has been shown to influence the accuracy of memory; younger witnesses are more suggestible and are more easily swayed by leading questions and misinformation.

7. Other factors, such as personal biases, poor visibility, and emotional tone of the event can influence eyewitness testimony.

(Boundless Psychology, 2016).

A more confident witness does not necessarily mean they are an accurate one. In some studies, researchers ask participants to judge how confident they are about the accuracy of their eyewitness testimony (Matlin & Farmer, 2016). Interestingly, in many situations, participants are almost as confident about their misinformation based memories as they are about their genuinely correct memories (Matlin & Farmer, 2016). In other words, people’s confidence about their eyewitness testimony is not strongly correlated with the accuracy of their testimony; the correlations are typically +0.30 and +0.50 (Matlin & Farmer, 2016). A survey of law enforcement officers in the U.S. showed that only 21% of the officers were aware that memory confidence is not strongly correlated with memory accuracy (Matlin & Farmer, 2016). Unfortunately, jury members are also more likely to believe a confident eyewitness than an uncertain one, however, the research does show that a confident eyewitness is not necessarily an accurate one (Matlin & Farmer, 2016).


Keep in mind that around 200 people per day in the U.S. become criminal defendants after being identified from line-ups and photo spreads (Loftus, 2018). The growing number of wrongly convicted individuals who have been exonerated by DNA evidence has given the world a real appreciation of the problem of faulty eyewitness memory, which is the major cause of wrongful convictions (Loftus, 2018). As for the case concerning Ricardo Guerra, who was mentioned in the beginning, the federal courts found the prosecution had intimidated witnesses, conducted a suggestive lineup, hidden exculpatory evidence, and injected false evidence into the trial (Death Penalty Info, 2001). The charges against Mr. Guerra were dropped, he was convicted in 1982 and exonerated in 1997 (Death Penalty Info, 2001). Mr. Guerra was Hispanic and the victim was white (Death Penalty Info, 2001).


Boundless Psychology. (2016). Considerations for Eyewitness Testimony. Retrieved from

Death Penalty Info. (2001). Summaries of 46 Cases in which Mistaken or Perjured Eyewitness Testimony put Innocent Persons on Death Row. Retrieved from

Loftus, E. (2003). Perspectives. Retrieved from

Loftus, E. (2018). Memory Faults and Fixes. Retrieved from

Matlin, M. W., & Farmer, T. A. (2016). Cognition. Retrieved from http://kaplan.vitalsource/#/books/9781119177678