Updated: Sep 11
How much can you trust your own eyes? If you were robbed, would you be able to correctly identify the perpetrator? According to psycholegal research, correct identification depends on many different factors, such as the conditions at the time of the crime (known as estimator variables) and the things that happen in the police station or courtroom later when you’re making the identification (known as system variables). For example, if the perpetrator were holding a gun, a different race than you, or standing in the shadows, you are less likely to make a correct identification (weapon focus effect, cross-race effect, and distance effect are all examples of estimator variables).
It is extremely concerning for the legal system that eyewitnesses are not always right. In fact, eyewitness identifications were involved in over 70% of cases of people who were wrongfully convicted of a crime and then exonerated with DNA evidence. One of the main contributions legal psychologists have made toward criminal justice reform is providing recommendations to the legal system to make it less likely that eyewitnesses make a bad identification due to things under legal system control (i.e., system variables). These recommendations were made in a White Paper (an authoritative report that can guide courts). Recently, Wells and colleagues (2020) released an updated White Paper with recommendations consistent with current research in Policy and Procedure Recommendations for the Collection and Preservation of Eyewitness Identification Evidence.
In the second Eyewitness White Paper, Wells and colleagues (2020) made nine research-based recommendations to police departments in order to reduce the likelihood of an eyewitness mistakenly identifying the wrong person:
1. Pre-Lineup Interviews – Interview a witness immediately after a crime and get a full description of the perpetrator
2. Evidence-Based Suspicion – Make sure there’s evidence against the suspect before putting them in a lineup
3. Double-Blind Lineups – Make sure the officer running the lineup doesn’t know who the suspect is (so they can’t give it away unintentionally)
4. Lineup Fillers – Have at least 5 people in the lineup that look similar to the suspect, but who you know are innocent
5. Pre-Lineup Instructions – Don’t give any information about the case before, and tell the witness that the perpetrator might not be in the lineup
6. Immediate Confidence Statement – Ask the witness how confident they are immediately after the identification, without any feedback
7. Video-Recording – Record the whole identification procedure (so juries can watch later and decide if it is coercive)
8. Avoid Repeated Identifications – Only show the lineup once
9. Showups – Never show just one suspect (showup)
Their recommendations primarily focus on the process of the police lineup, and while most are relatively simple and straight forward (ask the eyewitness how confident they are as soon as they’ve made an identification decision), some would require greater changes to the process (requiring evidence-based suspicion before allowing a suspect to be placed in a lineup). Although some of these recommendations might look unrealistic or as asking too much of a system already so resistant to change, we need to consider the alternatives. Furthermore, after the first Eyewitness White Paper, many police departments across the country started implementing these changes – showing that psycholegal research can impact policy. Either way, the question arises, how many more people do we want to send to prison or death row based on an eyewitness making a mistake?
Wells, G. L. et al(2020). Policy and Procedure Recommendations for the Collection and Preservation of Eyewitness Identification Evidence. American Psychological Association, 44(1), 3-36.