Police departments in Indiana and around the country use suspect lineups to make sure that they have the right individual in custody and to provide prosecutors with eyewitness identifications. Witnesses are usually asked to pick out the individual they observed from a collection of photographs. This approach can be unreliable, which is a problem because juries tend to find eyewitness identifications extremely compelling.
When photo arrays are used, witnesses are usually shown a picture of the suspect and five other people. Police officers call this a “six-pack.” Before the procedure begins, police officers are required to tell the witness that the array may not include a photograph of the suspect. In many other countries, police officers show witnesses more than six photographs, and they present them one at a time instead of all at once. This is referred to as the sequential lineup method, and it is considered to be far more reliable.
A witness who is asked to pick a suspect out of a photo lineup usually wants to please the police and do their part to fight crime. This does not mean they are biased, but it does make their identifications less reliable. When false identifications are made, it is often because the witness was influenced by the behavior of the police officers involved. Police officers tend to look more intently at the photograph of the suspect, and their facial expressions may convey to the witness who the suspect is. These are points that a criminal defense strategy may focus on during cross-examination.
Improving lineup procedures
Eyewitness identifications provide prosecutors with powerful evidence, but they are rarely as reliable as juries think they are. They would be more reliable if police officers showed witnesses photographs sequentially instead of simultaneously and looked away while the pictures are scrutinized. This is the procedure followed by law enforcement in many other countries, and it should become the standard photo lineup practice in the United States.