Released on parole, Tyronne Johnson, 43, walked out of prison a free man Tuesday morning. Unlike most inmates who come before a parole board, he did not express remorse for his crime. He maintained his innocence, as he has since the day he was arrested for the murder of Queens nightclub owner Leroy Vann 20 years ago.

In 2013, ProPublica investigated his case as part of a broader examination of prosecutorial misconduct in New York City.

Johnson said he sent the story to the parole board in a package of materials that also included documents tied to his prospects for employment, a record of good conduct while incarcerated and a plan for how he would continue to fight his case once out of prison. He now believes the story played a role in the board’s decision to release him.

“It’s the most thorough example of the truth of what happened,” he said. “I can’t just go up there and swear I was innocent.”

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ProPublica’s interest in the matter stemmed from the misconduct of Claude Stuart, the prosecutor who won the original conviction against Johnson. Stuart was the only New York City prosecutor who was publicly disciplined for misconduct in ProPublica’s analysis of 30 conviction reversals.

At issue was Stuart’s failure to disclose critical evidence at Johnson’s first trial. Stuart’s key witness was a man named Henry Hanley. He said he was paid to be a lookout from his home across the street from Vann, while Johnson and an accomplice murdered and attempted to rob Vann.

But Shanise Knight, Hanley’s aunt who lived upstairs from him, had told police that she saw a man much larger than Johnson shoot and kill Vann. Stuart had turned over her police statement, but he repeatedly said that he did not know where she was and could not find her.

Johnson was found guilty in the summer of 2002.

Within days, Johnson and his family began to work on an appeal, finding Knight immediately. In a sworn affidavit, she offered two shocking bits of information to an investigator: She said that Hanley was asleep downstairs during the shooting, and she said that she had spoken to Stuart and two detectives just two days before Stuart told a judge he could not find her. She later went on television and described her meeting with Stuart. Hanley then recanted his trial testimony.

In November 2002, then-Queens District Attorney Richard Brown wrote a letter to Judge Jaime Rios, who presided over the trial. Brown agreed to have Johnson’s conviction vacated, adding that Stuart’s conduct could not “be condoned.” Stuart resigned and Rios sent Brown’s letter to a disciplinary committee. That committee found that Stuart was involved in another act of misconduct years earlier, in which he insinuated that a gun found in the possession of a defendant at the time of his arrest was the same gun used in an attempted murder and robbery, even though a ballistics report showed that wasn’t true.

In 2005, the committee suspended Stuart’s license. In 2010, New York’s appellate division denied Stuart’s application to renew it.

Stuart did not immediately return phone calls seeking comment.

As for Johnson, his case was retried by the Queens DA in July 2003. This time, his lawyers succeeded in putting Knight on the stand. They also found an additional witness, Hanley’s girlfriend, who said she was asleep with him at the time of the murder.

Read More Lasting Damage: A Rogue Prosecutor’s Final Case Claude Stuart, after a career full of trouble as a prosecutor in Queens, finally went too far when he lied to a judge in an effort to convict a man of murder.

Hanley, however, recanted his recantation during a prison visit from the high-level Queens Assistant District Attorney Eugene Reibstein, who took over for Stuart. At the second trial, he repeated his original testimony, as did Leroy Vann’s mother, Mary Puryear, who said that her son’s dying words were: “Tyronne shot me.” Johnson was convicted again.

But the controversy continued. Following the second trial, the judge’s law clerk wrote a letter to the New York State Commission on Judicial Conduct, accusing the judge of coaching Reibstein. In a letter back to the clerk, the Commission thanked her and said the complaint “enabled the Commission to take appropriate action” and that it served a “useful purpose,” but did not elaborate. Rios remained on the bench until his retirement in December 2013.

Johnson’s lawyers filed a motion to vacate the conviction. A judge, reviewing that motion, ruled that while the conversation “strayed into improper territory,” it did not prejudice the verdict.

Johnson believes he never received a fair trial. On Thursday morning, he was scheduled to present his case in person to the Queens DA’s Conviction Integrity Unit. He is hopeful that Melinda Katz, the new DA, will initiate a review of the case, including DNA testing of a knit cap and other items found at the scene of the crime.

Celebrating with friends and family at his wife’s home in Coram, on Long Island, Tuesday night, Johnson was adamant that he did not regard his release as a victory.

“The turf just changed,” he said, meaning he would no longer be fighting to prove his innocence from inside a prison cell. “But the war is not over.”