Mistaken eyewitness identifications responsible for bad convictions, expert says

(CBS) -- Mistaken eyewitness identifications are the principal reason for more than 75% of mistaken convictions, says Dr. Robert Shomer.

Shomer, an eyewitness expert on this weekends show "48 Hours: Presumed Guilty," has testified as an expert for more than 1000 eyewitness trials in twenty states.

In doing extensive scientific research on all the factors that influence eyewitness identification, Shomer has concluded that the level of identification accuracy is very low and the confidence of the eyewitness is only weakly related to the accuracy of their identification.

Shomer says there are many examples of cases that lack substantial, independent evidence connecting a person to a crime. The only proof that some cases have is mistaken eyewitness identifications.

He says some common misconceptions tied to eyewitness identification are:

1. All that is needed to make an accurate identification is enough time to see someone, enough light, and an absence of excessive distance.

2. The type of identification procedure used by the police is not very important because the image of the individual seen was stamped into the memory of the eyewitness.

3. If the eyewitness expresses their identification with certainty it must be accurate because they had no other reason to make the identification.

All of these points have been refuted by repeated scientific studies.

Flawed eyewitness identifications are mainly due to inadequate and suggestive identification procedures used by police all over the country, says Shomer. Police officers rarely receive formal training in valid identification procedures and there is a lack of written police department policies on how these procedures should be carried out.

Shomer believes it is important that the public is educated on eyewitness identification and the police procedures that surround it. Anyone can be identified but whether or not that identification is accurate depends on many factors.