For more than two decades, Anthony Wright has insisted that he did not rape and kill 77-year-old Louise Talley in Nicetown.
He was working construction at the time of her death, he has said, adding that his confession came only after coercion from police, who he says threatened him while he was handcuffed to a chair.
And the bloodstained clothes that police removed from his house? Not his either, he has maintained.
He has made these claims from behind bars, where he is serving a life sentence for the 1991 slaying.
DNA testing sophisticated enough to exonerate him was not available in 1993, when a jury found him guilty, but it is now. And so for nine years his attorneys have pushed to see if advances in technology would support his case.
The results of those tests are back. They show it was someone else's DNA found in bodily fluids taken from the victim, say his attorneys, with the Innocence Project at Yeshiva University's Benjamin N. Cardozo Law School.
That DNA, the attorneys say in court pleadings, belonged to a career criminal and crack addict named Ronnie Byrd, who died early last year in South Carolina.
The bloodstained clothes, they say, turn out not to bear Wright's DNA either. The garments belonged to the woman who was killed.
Wright's attorneys plan to argue before Common Pleas Court Judge D. Webster Keogh on Monday that this new evidence - combined with statements from trial witnesses that detectives coerced them into testifying against Wright - is enough to warrant a new trial for the 43-year-old.
There is no sign the Philadelphia District Attorney's Office is about to concede the case.
On Aug. 15, prosecutors moved to dismiss Wright's motion for a new trial, citing the "utterly overwhelming evidence of [his] guilt.
"The defendant could never establish that he is innocent, regardless of the recent DNA results," wrote Assistant District Attorney Barbara R. Paul. "Indeed, that evidence is so overwhelming that the DNA evidence proffered here - although raising the possibility of a second perpetrator - does not come close to exculpating" Wright.
Prosecutors cited witnesses who said they saw Wright enter and leave Talley's house in the 3900 block of Nice Street.
Mostly, however, prosecutors cite Wright's own statement to homicide detectives, which they say explains the lack of his DNA in the victim's body.
The defendant admitted to rape, according to the prosecution's motion, but said he was not able to finish the act, so he did not leave DNA evidence.
Peter Neufeld, codirector of the Innocence Project, called the prosecutors' response to the evidence "very surprising."
In cases with similar DNA evidence, Neufeld said, "prosecutors almost invariably consent to vacating the conviction."
If the District Attorney's Office argues that an accomplice was involved, that would contradict the eyewitness accounts and confession that were the basis for the original prosecution, Neufeld said. He said he hoped that the prosecutor's position would change in time for the hearing.
"We can only surmise the reason is that higher people in office have not reviewed the evidence," Neufeld said.
Wright's legal team includes Neufeld and Nina Morrison of the Innocence Project, as well as Samuel W. Silver and Rebecca Lacher of Schnader Harrison Segal & Lewis L.L.P. in Philadelphia and Center City lawyer Sondra R. Rodrigues.
Although DNA is often seen by the public as the gold standard of proof, the absence of DNA evidence does not necessarily lead to a not-guilty finding in court.
Earlier this year, for example, Antwon Watkins, a 16-year-old South Philadelphia High School junior, was convicted by a Family Court judge of simple assault for a Jan. 13 incident in which he allegedly pointed an air rifle at police.
Watkins had several alibi witnesses, and school records showed he was in school at the time of the incident. His DNA was nowhere on the air rifle, which the suspect dropped as he fled police.
But the judge found Watkins guilty, appearing to be convinced by two veteran police officers' identifications of Watkins and the prosecution argument that DNA could have been wiped clean.
"What's significant here isn't just that Tony Wright's DNA is absent," Silver said. "It's that DNA testing has now identified another man - someone the jury never heard a word about - as the real perpetrator of these crimes."
Wright was 20 when he was arrested. His son, Anthony Jr., was 3. Now 27, the younger Wright works for a nonprofit educational organization and has three stepchildren and a child on the way with his fiancee.
Asked what he would say to District Attorney Seth Williams, Wright replied: "You know what's right and what's wrong. We lost a lot of time. I would hope you step up and right what's wrong."