Eyewitness misidentification is the single greatest cause of wrongful convictions nationwide, playing a role in more than 75% of convictions overturned through DNA testing.
While eyewitness testimony can be persuasive evidence before a judge or jury, 30 years of strong social science research has proven that eyewitness identification is often unreliable. Research shows that the human mind is not like a tape recorder; we neither record events exactly as we see them, nor recall them like a tape that has been rewound. Instead, witness memory is like any other evidence at a crime scene; it must be preserved carefully and retrieved methodically, or it can be contaminated.
When witnesses get it wrong
In case after case, DNA has proven what scientists already know – that eyewitness identification is frequently inaccurate. In the wrongful convictions caused by eyewitness misidentification, the circumstances varied, but judges and juries all relied on testimony that could have been more accurate if reforms proven by science had been implemented.
Why witnesses get it wrong
Several variables play a role in the accuracy of eyewitnesses identification, such as:
- Distance from the perpetrator
- Lighting conditions
- Race of the witness and race of the perpetrator (identifications have proven to be less accurate when witnesses are identifying perpetrators of a different race)
- Presence of a weapon
- Degree of stress or trauma a witness experienced while seeing the perpetrator
For real life examples of this phenomenon, please read the story of Larry Johnson.
How police can improve witness identifications
- Blind admininstration, where the officer administering the photo or live line-up does not know who the suspect is, so that he/she cannot provide conscious or unconscious clues to the witness
- Sequential photo arrays, where the witness sees a number of photos one at a time, have been shown to provide a higher degree of accuracy than simultaneous photo arrays
- Complete descriptions of the perpetrator should be gathered by police from each eyewitness before the line-up is conducted
- Standardized instructions given to each eyewitness
- Documentation by police of all of the witness's statements