Is seeing believing? Should courts believe witnesses when they testify to what they claim they saw with their own eyes? Maybe not, if the scientific evidence about eyewitness testimony is any indication. Here is why eyewitness testimony is something that your criminal defense attorney is likely to challenge in court and some examples of how he or she can do so.

Eyewitness testimony is often wrong

In three out of every four cases where DNA evidence has later been used to establish someone's innocence and overturn their conviction on appeal, that conviction relied largely on eyewitness testimony. Unfortunately, juries tend to believe people when they say that a particular event is stuck in their mind because of how terrifying it is—even though research repeatedly shows that the opposite is actually true. People who are shocked or scared or afraid of violence are actually less likely to have a clear memory of events than those who aren't.

There's a strong relationship between confidence and accuracy

One area of attack that your attorney may have on any eyewitnesses used to identify you in a photo or physical lineup is the relative confidence exhibited by the witness from the very beginning. Studies have shown that there's some relationship between the confidence level of a witness during early identification procedures, not the confidence shown at an actual trial, and the actual level of accuracy of that witness.

For example, a witness who is confident from the beginning of her identification of her rapist when shown an array of suspect photos is more likely accurate than the witness who hesitates and expresses doubt by saying something like, "I think this is him." 

The relationship is significant enough that experts believe that juries should be instructed to consider the confidence level shown by witnesses during early testimony and identification procedures, not the confidence that they exhibit during the trial after they have had months to convince themselves that they made the "right" identification early on. Your attorney may be able to argue this point in front of a jury or convince the judge to give those instructions before the jury deliberates.

Witnesses may also be subtly influenced by others.

Witnesses can also be subtly influenced by others during the early identification process in ways that neither they nor their interviewers realize. For example, some city and state police forces have taken measures to improve the accuracy of eyewitness testimony by doing such things as making sure that the investigator controlling the lineup of people from which the witness is asked to identify the perpetrator doesn't actually know who the suspect is. That can help ensure that the investigator doesn't give off any micro-signals, unintentionally or not, that could guide a witness toward identifying the "right" person in the lineup.

Your attorney is likely to ask a lot of questions about what procedures were used during early witness examination to make sure that their memories weren't contaminated by the investigators. He or she may be able to argue that a witness is only "sure" of his or her identification because he or she feels validated by the fact that you were the person the police suspected.

For more information on how a criminal defense attorney can attack seemingly strong evidence in a criminal case against you, discuss your case with an attorney in your area.