Often, it is the testimony of an eye witness that determines the outcome of a criminal case. In fact, a prosecutor’s main evidence in a case typically relies upon an eyewitness’s identification of the offender. Multiple, consistent identifications strengthen the prosecution’s case, more times than not. However, mistaken identification is common and has led innocent individuals to have to spend time behind bars. It is not an exact science.

Procedures for Eyewitnesses
The following are three, common eyewitness identification avenues during pretrial:

  1. The lineup. Commonly, five or six individuals will be asked to stand before an eyewitness. Often, one of those individuals is the suspect and the other are known as “decoys.” These individuals typically resemble the suspect in at least one way.
  2. Photo identification. During this procedure, an eyewitness is asked to look at photos to identify the suspect. Commonly, the photographs are mugshots that a police department has on file.
  3. Showups. A one-on-one identification procedure is called a showup. During a showup, the eyewitnesses are asked to look at a lone suspect to see if he or she is the person they believe to have committed the crime. This procedure is often viewed by the defense as too suggestive, as the eyewitnesses only have one suspect to look at.

Typically, the eyewitnesses are asked to testify in court about the procedure used to identify the suspect. Then, in the courtroom, each eyewitness is asked again if the defendant sitting there is the one they strongly believe committed the crime.

Reasons for a Mistaken Identity
Through experiments, psychologists have discovered several main factors that commonly lead an eyewitness to make a mistaken identity, including not getting a long enough look at the suspect to really know what he or she looks like. The following are just some of the other factors that could lead to a wrongful identification:

  1. If a person was under a great deal of stress during the time of the crime, he or she may not have the ability to accurately point out the perpetrator.
  2. Often, if a gun is used during the crime, the victim spends more time focused on the weapon than the criminal and may not truly know what the offender looks like.
  3. If the suspect is of a racial group differing from that of the eyewitness it is more difficult to accurately identify the offender.
  4. When pressure to point out a suspect exists, an eyewitness is more likely to make a mistake during the identification process.
  5. Commonly, discussing the incident with other eyewitnesses can lead an individual’s memory of the suspect to be altered.

Error Protection
During a trial, a cognitive psychologist often is called upon to discuss existing research highlighting the likelihood of a mistaken identification by an eyewitness. Typically, the psychologist goes over the factors involved that typically lead to an identification error.