Tuesday, June 10, 2008

Mistaken Identification

One of the most disturbing courtroom moments is when a witness points at the defendant and with confidence tells the jury that that is the person he or she saw leaving the scene of the crime. The number of mistaken identifications that lead to wrongful convictions is difficult to estimate.

It is important to understand why people misidentify other people. Most people have little or no problem picking out a friend in a crowded room, but this is not the same thing as recognizing the faces of strangers. Some facial features are more valuable than others. There are three dimensions that are most important, regardless of whether subjects looked at male or female faces, or black/white. These dimensions are the age of a face, facial shape and hair.

In some cases the witness is given the description of the suspect before he or she views a lineup. The lineup that is shown to the witness has the suspect with similar descriptions. Minutes later the witness identifies the person that she or he was told the suspect looked liked.

One way to determine if the witness was given information about the suspect before she identified him is to obtain the same lineup photo. Sometimes the lineup is obviously unfair; it may have 5 pictures of suspects that are older photos and 1 recent picture of the suspect they want identified. In some cases the witness may pick the wrong picture and the investigator may ask "are you sure it's not number 3?". These type of questions cause the witness to choose number 3, because of the investigator's suggestive comment. Another way witnesses are manipulated into picking a suspect is the way the investigator shows the lineup. The investigator may put the pictures down one at a time and ask the question "is this the person you saw". As he goes through the photos he pauses on the suspect they are focusing on. This causes the witness to pick a particular photo and the investigator may or may not show the witness the rest of the lineup because he or she has identified the suspect who they believe committed the crime.

Nature Publishing Group has an excellent article, “Line-ups on Trial” that delves further into this issue that can be found here:

http://www.psychology.iastate.edu/faculty/gwells/Nature_article_May_2008.pdf

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