DETROIT (AP) — A man has been released from prison after 22 years after Detroit-area prosecutors acknowledged that his murder conviction was tainted by the key testimony of a rogue police officer who turned out to be a serial bank robber.

“Not much shocks me anymore, but this did,” Wayne County prosecutor Kym Worthy said. “I have never seen anything like this in all of my decades of being a judge or a prosecutor.”

LaVone Hill was sentenced to life in prison following his 2002 conviction in the fatal shooting of two men.

Investigators had a signed statement from a man who said he had witnessed the shooting. But at trial, he recanted and said he had been coerced by police.

The jury also heard from Detroit police Sgt. Walter Bates, who denied coercing the witness. The jury apparently believed the officer and declared Hill guilty.

But Worthy noted that jurors and Hill’s lawyer didn’t know that Bates was suspended at the time of his testimony. Bates was later convicted in federal court of organizing bank robberies.

“I cannot say whether (Hill) is guilty or not guilty of this crime,” Worthy said. “This is what I can say definitively: Former Sgt. Bates’ testimony in Mr. Hill’s trial was a pivotal part of his case. No one during the trial — not the assistant prosecutor, not the defense attorney, or the judge — was made aware of Bates’ massive and ongoing criminal behavior before, during and after the investigation and trial.”

Bates declined to comment when reached by The Detroit News.

Hill, who has repeatedly declared his innocence, was released from prison Wednesday. He was represented by the Innocence Clinic at University of Michigan law school, which uncovered other problems with the case. The clinic said the victims were shot by a rifle, not a handgun, as the jury was told.

“I was not even there when this crime took place,” Hill told a judge. “I’ve sat in prison for almost 23 years because of the misconduct of the Detroit Police Department.”