UPDATE SAVANNAH, Ga. (AP) — A federal judge ruled Tuesday that Georgia death row inmate Troy Anthony Davis, whose case attracted international support failed to prove his innocence after the U.S. Supreme Court gave him a rare chance to clear his name.

Troy Davis has spent nearly 20 years on Georgia’s death row for the 1989 slaying of an off-duty Savannah police officer. Davis has long claimed new evidence would clear his name, if only a court would hear it.

The NAACP, Amnesty International and dignitaries such as former President Jimmy Carter and Pope Benedict XVI have rallied behind Davis. A year ago, the U.S. Supreme Court granted Davis a federal hearing to put his innocence claim to the test – a chance afforded no other American in at least 50 years.

U.S. District Judge William T. Moore Jr. said the evidence presented by Davis’ attorneys at a June hearing wasn’t nearly strong enough to prove he’s innocent.

“Ultimately, while Mr. Davis’s new evidence casts some additional, minimal doubt on his conviction, it is largely smoke and mirrors,” the judge said.

The ruling sets the stage for Georgia officials to resume planning Davis’ execution, though his attorneys vowed to appeal.

Davis, 41, was convicted of murder in 1991 for the slaying of Mark MacPhail, who was shot while rushing to aid a homeless man being attacked outside a bus station.

The Supreme Court’s decision to grant Davis an evidentiary hearing was extraordinary because federal death penalty appeals normally look only at questions of due process and constitutional violations, not guilt or innocence.

Witnesses at Davis’ June hearing testified they lied at his trial when they said Davis confessed to the killing. Others said another man later told them he, not Davis, shot MacPhail.

The judge said the witness’ claims weren’t strong enough to have swayed an average juror.

“We strongly disagree with the court’s findings and conclusions,” said Stephen Marsh, one of Davis’ attorneys. “We believe that Troy is innocent.”

The victim’s mother, Anneliese MacPhail, said she was pleased by the ruling but nervous it may not stick.

Davis has been spared from execution three times since 2007.

“I’m not holding my breath,” MacPhail said. “We’ve been through too much to think this is over soon.”

Associated Press writer Greg Bluestein in Atlanta contributed to this report.

Copyright 2010 The Associated Press.