Charges have been dropped against a man who spent nearly three decades behind bars before DNA evidence cast doubt on his murder conviction, prosecutors in Florida said Wednesday.

William Dillon, 49, has been free on bond since last month, after a judge ordered a new trial because of testing that showed his DNA wasn't on key evidence from his 1981 conviction.

Prosecutors subsequently concluded that a jury wouldn't find Dillon guilty "beyond and to the exclusion of every reasonable doubt," Brevard County State Attorney Norman Wolfinger said Wednesday.

Aside from the DNA test results, nine witnesses from Dillon's trial have died, and another cannot testify because of medical problems.

Mike Pirolo, Dillon's public defender, described Wednesday's development as bittersweet.

"Sweet that justice was done and he's a free man," he said. "Bitter that 27 years of his life was taken away that he'll never get back."

Two other inmates also spent 27 years behind bars before being exonerated by DNA evidence, the longest such terms, said the Innocence Project, a legal center specializing in wrongful conviction cases.

Testing for DNA evidence wasn't available when Dillon was originally tried in the bludgeoning death of James Dvorak.

New analysis paid for by the Innocence Project Florida showed Dillon's DNA was not found on a bloodstained yellow T-shirt presented during his trial. The victim's blood was on the shirt, along with the DNA of two other people.

Dillon didn't immediately return a message left Wednesday with defense attorneys.

He had expressed relief when he was released last month.

"When I first went behind the bars, I couldn't believe that it happened," Dillon said at the time. "And then I never thought it was gonna be corrected."