(January 02, 2009)—It’s an issue that continues to plague the judicial system: innocent citizens are convicted of a crime based on faulty eyewitness testimony.

Several cases in Dallas have recently been overturned with DNA testing where the wrong suspect was picked in a photo lineup.

The Dallas Police Department will now study its witness I.D. methods in an effort prevent false convictions.

Usually a detective shows a witness at least six pictures of possible suspects at one time.

Critics however argue the detective's physical and verbal cues can unintentionally taint results.

As part of the study, Dallas police will use "sequential blind lineups" in which someone who doesn't know who the suspect is shows the photos one at a time.

Experts say the wrong person is less likely to be chosen that way.

Witnesses will not be able to compare one person to another and pick someone who resembles the criminal.

The Urban Institute, based in Washington D.C., is overseeing the Dallas study which is to begin early this year.