"I was too young back then to realize that this was a setup. To me this was just basically, I never saw a lineup before, I was just part of the process," Lieberman said in an exclusive interview with CNN's AC360 on Thursday. "I think as years went by ... as more and more I saw on the news, I saw innocent people get set free in various ways. I started to think back to the trial I was involved in, and remembered where I was told who to pick out of the lineup."

After Lieberman came forward, O'Mara's unit began to dig into Ranta's case.

"As he started to investigate, the whole case fell apart," Lieberman said. "So I guess an innocent man was in jail but is now free. The sad part is that the killer never met justice."

For some, doubts linger

Isaac Abraham, a friend of the victim's, said he had sat through the trial and came away convinced that if Ranta had not been Werzberger's killer, "he was definitely an accomplice."

"Now it's David Ranta's day to suck in some fresh air and enjoy his free life out there," Abraham said. But he said the decision to release him left him "confused."

"Is the shooter still out there? We're pointing to a dead man to close the case? That's asinine," he said.

Werzberger died four days after being shot, a victim of the attempted holdup of a diamond courier. The courier escaped, but the would-be robber shot Werzberger through the window of his parked car, hauled him out of the vehicle and drove off, according to the Brooklyn district attorney's office.

Ranta was arrested six months later, when two men facing trial on their own robbery charges gave his name to police, prosecutors recounted in asking that his conviction be tossed out.

In an initial lineup, only one witness recognized Ranta, and that was after a lengthy conversation with a Yiddish interpreter, they noted. In the second lineup, three youths identified him and repeated that identification in court. One witness who didn't identify him was the courier, the intended target of the holdup.

Attorney: 'There was no physical evidence'

When questioned by detectives, Ranta initially denied any involvement in the killing. Then he acknowledged knowing one of the jail inmates who identified him, according to prosecutors. He admitted he had been near the scene and knowing his friends had planned a holdup. Then he admitted he had been involved in planning the diamond heist, acted as the lookout and had seen the other men with the gun.

"The police had an alleged confession from him, but there was no physical evidence," Michael Baum, the lawyer who represented Ranta at his trial, told CNN. "The jewelry courier, he testified for the defense, saying that Ranta wasn't the guy."

Four years after Ranta's conviction, a woman named Theresa Astin came forward to say her husband had been the killer. Joseph Astin, who had died in a 1990 car accident, had been possible suspect before: Scarcella had brought the courier to the morgue in hopes that he could identify Astin as the gunman, but he couldn't.

Baum sought a new trial for his client based on the widow's testimony, without success. Then in 2011, Lieberman came forward.

"It was on his conscience for all these years," Baum said. "He was 13 years old at the time. He was just a kid. He was just doing what they told him to do."

Detective: 'I never framed anyone'

As O'Mara began to dig into the case, details unraveled. One of the two jail inmates who put the finger on Ranta had since died; the second told prosecutors he had fabricated earlier statements he made about Ranta, hoping that his cooperation would help his own criminal case. His girlfriend at the time confessed that her account was manufactured as well. And Theresa Astin reiterated her previous testimony.

Scarcella said the case against Ranta was "very simple," and he sharply disputes Lieberman's account of being coached.

"They're saying that I framed it," Scarcella said. "I want to go on record saying this: I never framed anyone in my life, and you would have to be a low, low devil to do something like that. I slept very good for the last 22 years."