ATLANTA - A defense attorney says Georgia prison officials have blocked inmate Troy Davis from taking a polygraph test before his scheduled execution.
Attorney Stephen Marsh told The Associated Press on Wednesday that the Georgia Department of Corrections has denied his request to allow Davis to take a polygraph test. Davis is scheduled to die at 7 p.m. EDT Wednesday.
Davis has long claimed he is innocent of killing Mark MacPhail, an off-duty police officer working as a security guard in Savannah, Ga. But state and federal courts have repeatedly upheld his conviction.
Prosecutors and MacPhail's relatives say they have no doubt the right man is being punished.
Marsh had said he hoped the polygraph test would convince the state pardons board to reconsider a decision against clemency.
On Wednesday, supporters planned vigils outside Georgia's death row prison in Jackson and protests at U.S. embassies in Europe. Davis' attorneys planned another late appeal, this one aimed at blocking the execution by convincing a judge that some of the original evidence was questionable.
(At left, watch a "CBS Evening News" report on efforts to exonerate Davis)
Some witnesses who fingered him at trial as the shooter later recanted, and others who did not testify came forward to say another man did it. But a federal judge dismissed those changed and new accounts as "largely smoke and mirrors" after a hearing Davis was granted last year to argue for a new trial, which he did not win.
Davis didn't want a last meal. He planned to spend his final hours meeting with friends, family and supporters. According to an advocate who met with him late Tuesday, he was upbeat, prayerful and expected last-minute wrangling by attorneys.
Davis has received support from hundreds of thousands of people, including a former FBI director, former President Carter and Pope Benedict XVI. Some of his backers resorted to urging prison workers to strike or call in sick Wednesday, and they considered a desperate appeal for White House intervention. And some of Davis' supporters were considering whether to ask President Obama to intervene, a move that legal experts said was unlikely.
In Europe, where the planned execution has drawn widespread criticism, politicians and activists were making a last-minute appeal to the state of Georgia to refrain from executing Davis. Amnesty International and other groups planned a protest outside the U.S. Embassy in Paris later Wednesday and Amnesty also called a vigil outside the U.S. Embassy in London.
Parliamentarians and government ministers from the Council of Europe, the continent's human rights watchdog, called for Davis' sentence to be commuted. Renate Wohlwend of the Council's Parliamentary Assembly said that "to carry out this irrevocable act now would be a terrible mistake which could lead to a tragic injustice."
The U.S. Supreme Court gave him an unusual opportunity to prove his innocence last year, but his attorneys failed to convince a judge he didn't do it. State and federal courts have repeatedly upheld his conviction.
MacPhail's family lobbied the pardons board Monday to reject Davis' clemency appeal. The board refused to stop the execution a day later.
"He has had ample time to prove his innocence," said MacPhail's widow, Joan MacPhail-Harris. "And he is not innocent."
Spencer Lawton, the district attorney who secured Davis' conviction in 1991, said he was embarrassed for the judicial system that the execution has taken so long.
"What we have had is a manufactured appearance of doubt which has taken on the quality of legitimate doubt itself. And all of it is exquisitely unfair," said Lawton, who retired as Chatham County's head prosecutor in 2008. "The good news is we live in a civilized society where questions like this are decided based on fact in open and transparent courts of law, and not on street corners."
Davis supporters said they will push the pardons board to reconsider his case. They also asked Savannah prosecutors to block the execution, although Chatham County District Attorney Larry Chisolm said in a statement he was powerless to withdraw an execution order for Davis issued by a state Superior Court judge.
"We appreciate the outpouring of interest in this case; however, this matter is beyond our control," Chisolm said.
Davis' lawyers drew up a late appeal asking a local judge to block the execution over evidence they object to. Defense attorney Brian Kammer told The Associated Press he would file the appeal in Superior Court in Butts County, home of the state's death row, when it opens Wednesday.
The motion disputes testimony from a ballistics examiner who claimed that the bullets fired in a previous shooting that Davis was convicted of may have come from the same gun that fired at MacPhail. And it challenged eyewitness testimony from Harriet Murray, a witness who claimed at the trial to have identified Davis as the shooter.
It asks the court to vacate Davis' execution, or at least delay it by 90 days, on grounds that it was "based on false, misleading and materially inaccurate evidence."