Texas joined nine other states and passed a measure that requires police departments across the state to review their eyewitness procedures.

For decades, psychological scientists have worried that the traditional way police departments have conducted these photo lineups was flawed and was landing many innocent people in jail. There was a better way, they argued, and police departments needed to change.

Last month, the state of Texas joined nine other states and passed a measure that requires police departments across the state to review their eyewitness procedures. The law suggests that departments seriously consider the kinds of research-based reforms that psychological scientists have been talking about for years. This move by Texas — a strong law and order state — suggests the science of the lineup is steadily making its way out of the lab and moving to a police station near you.

"We look for cues in our environment to decide what's an appropriate answer — what's an appropriate response. That's human nature," says Gary Wells, a psychologist at Iowa State University who studies police lineups.

By staging crimes and analyzing the way that his witnesses pick out his suspects, Wells has uncovered all kinds of things about lineups that were previously hidden. This work has led Wells and other researchers to suggest a series of reforms.

For example, one reform Wells suggests is that the officer conducting the lineup should not know which person in it is the actual suspect. Otherwise, Wells says, that officer will unconsciously communicate to the witness who the suspect is.

"It's just not really possible for people who know an answer to perform these kinds of tasks in a totally neutral way," says Wells.

Researchers like Wells also argue that witnesses should be told before viewing the lineup that the actual criminal might not be present. According to research, including that simple caveat will change the rate at which people are picked from lineups.

Finally, Wells says, instead of showing the pictures all at once — which encourages the witness to compare the people in the lineup with each other —photos should be shown one at a time, because doing it that way encourages people to compare the person they're looking at with the person they have in their head, which seems to result in fewer innocent people getting picked.

Link:
http://www.npr.org/2011/07/06/137652142/to-prevent-false-ids-police-lineups-get-revamped