A wise Jedi once said, “Your eyes can deceive you, don’t trust them.” He was right, and many innocent people have gone to jail because of this. Mistaken eyewitness testimony is the number one cause of innocent people ending up behind bars with 75% of all exonerations involving mistaken eyewitness testimony in the conviction, according to the Innocence Project.
Memory is not like a video recording that can be played back. Every time we recall a memory we are altering the neural connections of our brain. Our assumptions, beliefs, and environment go into a memory. Here is an example: What does txt msg mean? Your brain fills in the blanks to create the word text message based on previous experience. Most of the time, we are not even aware we are doing this, and sometimes our brain fills in information that is not really there.
The object of your attention greatly influences your memory. It has been found that in crimes involving weapons, people are less likely to recognize the face of the perpetrator. One study by Loftus involved two pictures which were identical save for that in one a person was holding a gun and in the other they were holding a checkbook. People were less able to determine the details of the person in the first picture.
Police lineups are also a breeding ground for error. Generally, people will pick the person who is the closest approximation to their memory. In one study, 54% of eyewitnesses were able to identify the actual culprit from a 6 person lineup with 21% making no identification. When the culprit was removed, the rate of no identification rose only to 32%, with the remaining 68% mistakenly identifying someone from the remaining 5 person lineup. When eyewitnesses were given specific instructions that the culprit may or may not be in the lineup, misidentification was reduced by 41.6% in culprit absent lineups.
Who administers the lineup, whether photo or physical, also has a large impact on influencing the eyewitness. If the administrator knows which person is the suspect and who are the fillers, there is a higher chance of the eyewitness picking up cues and identifying the suspect. Confirming eyewitness choices by informing them that they picked the suspect also greatly increases their certainty in their choice.
Once a person chooses a suspect, the image imprints upon their brain and they are extremely likely to pick the person again, even side by side with the actual culprit. One experiment involved people picking one of two pictures of people. Then two other pictures were shown, but the picture of the culprit was altered slightly. When the real picture and altered picture of the culprit were then placed side by side, people chose the altered picture as the true one.
Careful deliberation does little to improve proper identification. One study found that those who made their decisions in less than 10-12 seconds were 90% accurate while those who took longer were 50% accurate. This is because the act of deliberation involves creating a new scenario in your mind and summoning factors that make sense, but may not have actually been there. It is the brain trying to create a pattern in the event by filling in the blanks. The brain hates disorder.
Simons & Chabris, Selective Attention Test: http://www.youtube.com/watch?v=vJG698U2Mvo
Derren Brown, Person Swap: http://www.youtube.com/watch?v=vBPG_OBgTWg
Derren Brown, Paying with Paper: http://www.youtube.com/watch?v=3Vz_YTNLn6w
Simply Psychology, Eyewitness Testimony: http://www.simplypsychology.org/eyewitness-testimony.html
Stanford Journal of Legal Studies, The Problem with Eyewitness Testimony: http://agora.stanford.edu/sjls/Issue%20One/fisher&tversky.htm
PBS, The Magic of the Mind: http://www.pbs.org/wgbh/pages/frontline/shows/dna/photos/eye/text_06.html
Wired, How to Improve Eyewitness Testimony: http://www.wired.com/wiredscience/2012/04/how-to-improve-eyewitness-testimony/
Iowa State University Psychology Department, Eyewitness Testimony: http://www.psychology.iastate.edu/~glwells/Wells_articles_pdf/Eyewitness_Testimony_Ann_Rev.pdf
American Psychological Association, How Reliable is Eyewitness Testimony? http://www.apa.org/monitor/apr06/eyewitness.aspx
Yale Law School, Eyewitness Testimony Doesn’t Make it True: http://www.law.yale.edu/news/2727.htm
60 Minutes, How Accurate is Visual Memory? http://www.cbsnews.com/8301-18560_162-4848039.html
USA Today, States Change Police Lineups After Wrongful Convictions: http://usatoday30.usatoday.com/news/nation/2009-09-16-police-lineups_N.htm
Georgia General Assembly HR 1071: http://www.ripd.org/Documents/APPENDIX/3/Georgia.pdf
Harvard University, Priming and Multiple Memory Systems: http://dash.harvard.edu/bitstream/handle/1/3627272/Schacter_PrimingMultiple.pdf?sequence=2