Test results exonerated Dennis Maher, 42, of two rapes for which he was sentenced in Massachusetts in 1984 to life in prison.
"Overwhelming," Maher responded when reporters asked him how he felt now that he was a free man. "It's finally over. It's been 19 years." He said he felt a "sense of relief."
Maher was released from custody by Middlesex County Superior Court Judge Charles Grabau after a brief hearing at which prosecutors agreed he had been wrongly convicted.
"I offer my profound regret for what appears to be the failure of the system," said District Attorney Martha Coakley. She said the state "fully agrees to acknowledge Mr. Maher is innocent,"
Maher's parents - Donate and Lucy Maher of Lowell, Mass. -- relatives and others in the courtroom broke out in applause as Maher smiled widely.
Maher, who served with the Army Special Forces at Ft. Devens, Mass., before his arrest in 1983, became the 126th person to be exonerated by post-conviction DNA testing with the help of the New York-based Innocence Project, co-founded in 1992 by attorneys Barry C. Scheck and Peter J. Neufeld.
After seeing Scheck on television in 1993, Maher wrote to the project, which provides legal help to inmates where DNA testing might help establish innocence.
Maher, who was convicted primarily on the eyewitness accounts of the women he allegedly raped, became one of the project's earliest cases.
Proving he was not the rapist, however, was difficult because forensic evidence had been misplaced.
The breakthrough came in 2001 when a law student found evidence from one 1984 trial - the rape victim's pants and underpants - stored in a box in the basement of the court building.
Tests excluded Maher as the source of semen on the evidence. Evidence from his second trial -- a slide from the rape kit of the other victim -- was finally located in February at the Ayer, Mass., Police station.
The results of tests on that slide were received last week, and also proved Maher was not the rapist.
Based on those results, prosecutors agreed that Maher should be freed.
"When a horrible mistake has been made, it is our obligation to rectify it with all due speed," Coakley said. "Every once in a while a case like this gives us pause."
Innocence Project deputy director Aliza B. Kaplan said it was unfortunate that Maher has no legal remedy under state law to be compensated for his time in prison, nor receive any social services to help him return to society.
"Massachusetts currently has no compensation law for people who have been wrongfully convicted," she said.
Before leaving the courthouse, Maher expressed regret that, "I never had a chance to have a family, other than the family I have. I lost that opportunity."
Maher always insisted he was innocent, and said he never considered pleading guilty to get a lighter sentence because, "I didn't do the crime."
He said his service in the Army helped sustain him while in prison.
"Being a soldier is serving your country with honor," he said, "and you always believe in your country and believe in faith."