A 62-year-old man who spent more than half his life in prison for the 1975 murder of a high school classmate had his conviction overturned Wednesday after a case review found Long Island prosecutors had long hid the fact that police looked at another possible suspect.

Other red flags in the case that put Keith Bush behind bars for 33 years included Bush's claims that detectives used a telephone book to beat a confession out of him and a trial witness who later said she lied about seeing Bush and the victim together.

Suffolk County District Attorney Tim Sini, who went to court with Bush's lawyer seeking to have the conviction overturned, said it's clear to him that Bush did not kill 14-year-old Sherese Watson. He apologized to Bush on behalf of his office and the law enforcement community.

"I am truly humbled by this decision," Bush said.

Bush was 17 when Watson's body was found in a vacant lot in North Bellport. They had attended the same house party a few blocks away, and a witness who testified at Bush's trial said she had seen them leave together. That woman later said she lied.

Convicted of murder and attempted sexual abuse, Bush spent 33 years in prison. He was paroled in 2007 and moved in with his mother in Bridgeport, Connecticut, but has had to register as a sex offender.

The rush to convict Bush, who is black, came at a time when the forces policing and prosecuting crime in Suffolk County were almost exclusively white men and prone to cutting corners. Watson was also black.

When interviewed by Sini's investigators, a retired detective who worked on the case used a racist term to describe Bush and said "he should have been executed" for Watson's killing, according to a report filed with the DA's request to overturn the conviction.

Sini called the review and reversal of Bush's conviction "a window into a very dark aspect of Suffolk County's history."

During the investigation of Watson's death, detectives interviewed John Jones, who said he had stumbled over her body while drunk, but neither police nor prosecutors informed Bush's lawyers or the judge at his trial about the possible suspect.

The police department's interest in Jones, who had a long criminal record and died in 2006, finally came to light last year when authorities turned over his police statement in response to a lawsuit seeking case records filed by Bush's lawyer, Adele Bernhard. Bernhard runs the Post-Conviction Innocence Clinic at New York Law School.

The questions surrounding Bush's conviction led Sini to order his newly formed Conviction Integrity Unit to conduct a full review of the case.

The unit's nine-month investigation determined that it was "forensically impossible" for Watson to have been killed in the manner described in Bush's confession. The investigation also debunked the trial prosecutor's theory of how the crime unfolded.

Investigators reviewing Bush's case said that in an interview this year, the detective who took his confession alluded to using coercive tactics.

"All the evidence used to convict Mr. Bush is undermined or simply not true," Sini said. "In fact, there's evidence that goes to his actual innocence. There's a much more probable suspect, and that's John Jones."