It’s a familiar movie and television scene. The prosecutor asks the witness, “Do you see the person in this courtroom who committed the crime?”
“Yes, the defendant. I’m positive,” the witness points to the accused. This eyewitness statement leaves an indelible mark on the jury.
Eyewitnesses are convincing, but are wrong 1 out of 3 times. So says the American Psychological Association in its friend-of-the-court brief filed in August 2011 with the U.S. Supreme Court in the case of Perry v. New Hampshire.
Many studies have proven that eyewitnesses are unreliable. One study, Judging Innocence, by Prof. Brandon Garrett in the Columbia Law Review, looked at 200 cases in which defendants were exonerated by DNA. In 76 percent of the cases, an eyewitness identified an innocent defendant–65 percent of these eyewitnesses were victims of the crime.
Many years of research has proven that the human memory is not like a video recorder. Rather, people imagine and reconstruct what they have seen, retained, and recalled.
There are several reasons why witnesses often identify an innocent person.
Time Looking at the Perpetrator – A study showed that when eyewitnesses watched a perpetrator for 45 seconds, 85 percent were correct. However, when eyewitnesses watched a perpetrator for only 12 seconds, 30 percent were correct. Distance – People with normal vision can see clearly within 25 feet. After that, clarity diminishes and then disappears at 150 feet. Passage of Time – The memory decays substantially early on. A witness can misidentify an innocent person as the perpetrator even a few hours after the crime. Stress – Elevated stress can cause an eyewitness to confuse the identity of a perpetrator, especially if the witness is the victim of the crime. Weapon Focus – Eyewitnesses focus more on the weapon than the perpetrator. Cross-Race – Witnesses are more accurate in identifying people of their own race. Studies have shown that eyewitnesses who are not of the same race as the perpetrator tend to be 56 percent erroneous.
Seeing is believing, and a jury’s over-reliance on an eyewitness cannot be cured by cross-examination and jury instructions. Cross-examination by the defendant’s lawyer may expose some errors, but will not overcome an insistent eyewitness. A study concluded that jury instructions are ineffective in sensitizing a jury to the errors of eyewitness testimony. An expert witness, however, may be helpful in explaining to the jury the limits of an eyewitness.
Another familiar movie and television scene occurs during an investigation of a crime. The police show a photo to the witness and say, “Do you recognize this person?” The witness agrees that the person in the photo is the perpetrator.
This “show-up” is biased. The witness is merely confirming the police’s suggestion. Witnesses may want to help the police take a criminal off the street and agree with the police’s choice of the perpetrator.
In contrast, a line-up (when the witness chooses from a pool of people) tests the memory of an eyewitness. But even lineups can be unreliable, because the witness expects that someone in the lineup is the perpetrator. The same is true of a photo array of suspects.
In the Perry case, the defendant was convicted of stealing stereo equipment from a car parked in a lot. A witness testified that she saw the defendant commit the crime, although she viewed the well-lit parking lot from her second-story apartment across the street at 2:30 a.m. Later, the witness identified the defendant who was standing next to a police officer. Perry argues that the presence of the police officer suggested to the witness that he was the thief; the witness identification should not have been admitted into evidence at the jury trial.
Perry wants his conviction overturned. The U.S. Supreme Court will have the final say.