By Derrick Blakley

(CBS) — Police lineups are often used to identify the guilty, but too often, the results send innocent people to prison.

CBS 2’s Derrick Blakley takes a look at a new law that protects the innocent.

Over the last 25 years, more than 300 wrongful convictions nationwide have been overturned by DNA evidence. And behind most of those false convictions were false eyewitness identifications.

That’s what this new law is intended to correct.

Twenty-four years ago, Marcus Lyons was wrongly convicted of a Woodridge rape. It all began with a flawed lineup.

“That was all the evidence they needed and all the evidence they presented,” he tells Blakley.

The victim was shown a series of photos, but the only one dressed in a shirt and tie was Lyons.

“Marcus’ photo sticks out. Marcus was obviously the police suspect in that he was the only one that wasn’t portrayed in a mug shot. It was his work ID,” says Prof. Karen Daniel of Northwestern School of Law.

Based on the victims’ ID alone, Lyons served three years in prison.

“I was in a state of shock. I continued to tell them it’s got nothing to do with me,” he says.

But the new law would curb lineup abuses. Lineups must be conducted by an officer who doesn’t know who the suspect is. That prevents the cop “from either consciously or accidentally giving signals to the witness as to who the police think committed the crime,” Daniel says.

Lineups cannot have one suspect that sticks out like a sore thumb, and all lineups must be audio- or videotaped.

“That helps judges and juries see exactly what happens so they can make a decision on a defendant’s guilt,” says Kane County State’s Attorney Joe McMahon says.

“This is another step in helping us get it right,” he says.

DNA exonerated Lyons, but his injustice can’t be reversed.

“My intent was to finish school and go back to be a naval officer and all that’s been derailed,” he says.

McMahon says law enforcement now understands that videotaping protects them as well as criminal suspects. If a lineup is recorded, and properly conducted, it’s one less thing for a defense attorney to attack.