Julius Earl Ruffin knows all too well how inaccurate eyewitness identification can be.
On May 3, 1982, in a Norfolk, Va. circuit court, the 29-year-old was convicted of a rape that he did not commit and was sentenced to five life sentences.
The case rested solely on the testimony of the victim, Ann Meng, a young mother of three who confidently pointed to Ruffin as her assailant.
Twenty-one years would pass before Ruffin was able to prove his innocence with DNA evidence. He details his experiences in the book "Why Me? When It Could've Been You!"
Watch the story on "Primetime" tonight at 10 p.m. ET
Ruffin's story is not unusual. In fact, according to the Innocence Project, a non-profit organization that assists prisoners who can be proven innocent with DNA testing, mistaken eyewitness identifications contributed to more than 75 percent of the more than 200 wrongful convictions in the United States that have been overturned on the basis of DNA evidence.
"Primetime" wanted to see what would happen if we set up scenarios where we asked onlookers to identify the person involved in a purse snatching.
We hired actors to play the role of the victim and the thief. Because scientific research has found that race plays a significant role in the accuracy of a witness' ability to identify a perpetrator, we chose three different actors for the experiment: a Caucasian, an African-American, and a Hispanic.
Along the edge of Atlanta's Piedmont Park we positioned seven hidden cameras at Willy's Mexicana to capture the scene from every possible angle. The customers were unaware of what was about to interrupt a leisurely weekend lunch at the outdoor cafe.
In the first scenario Justin, the white actor playing the "thief," walked up to Elizabeth, the "victim," and asked if she had a pen that he could borrow, explaining that he needed to write down a phone number. And then, suddenly his whole demeanor changed.
"Give me your purse! Sit down! Don't move!" he barked at her. Justin quickly grabbed the handbag and ran away.
Elizabeth was horrified and asked the other customers if they saw anything, knowing she'd need witnesses to help pick out the thief.
At that point ABC News correspondent John Quinones walked over to let people know that what just happened was not an actual robbery but instead an experiment about eyewitness identification. John asked the people to describe the thief.
Joe Donnelly recalled that "he had blond hair, had a hat on, about 35, 6 feet 1 inch."
But William Stark described him as "late 20's, white male … I would guess 5 feet 10 inches maybe."
Both were certain they could pick him out of a lineup.
But when we showed the videotape of the experiment and the bystanders' reactions to Professor Jennifer Dysart of New York's John Jay College of Criminal Justice, a psychologist who consults on criminal cases, she was doubtful.
"Eyewitness memory … does have its downfalls though, in that it is particularly susceptible to influences and biases," she said.
To test this idea we put together a line-up with six headshots of different Caucasian men, including Justin's, and showed it to the customers from Willy's Mexicana who represented many different races and ages.
We asked why they chose the photos they did.
William Stark noticed Justin's facial features and his hat, but added, "It's not so much that I recognize him exactly, but I tried to eliminate the ones that I strongly felt were not the guy."