Supporters of convicted cop killer Troy Davis say time is running out.
Unless something dramatic happens, Davis will die by lethal injection next week for the 1989 murder of Savannah, Georgia, police officer Mark MacPhail.
Davis, 42, is set to be executed at 7 p.m. Wednesday, and since his 1991 conviction, seven of the nine witnesses against him have recanted or contradicted their testimony. No physical evidence was presented linking Davis to the killing of the policeman.
Many people fighting for Davis' life are feeling the pressure.
"We honor the life of Officer MacPhail," said Edward DuBose, Georgia state conference president of the NAACP, but he added, "You cannot right a wrong by offering up Troy Davis, who we believe is not the person responsible."
The NAACP joins several groups advocating for Davis, who also counts former President Jimmy Carter, Archbishop Desmond Tutu, Pope Benedict XVI and singer Harry Belafonte among his defenders.
The Rev. Al Sharpton's National Action Network plans to hold a candlelight vigil Friday for Davis at Atlanta's historic Ebenezer Baptist Church. Sharpton will speak at the rally at 7 p.m. ET.
Supporters Thursday delivered a massive petition containing more than 663,000 signatures in support of clemency for Davis.
They're worried that won't be enough, as all legal appeals have been exhausted and only the state Pardon and Parole Board can call off Wednesday's execution. The board denied clemency in 2008.
"In some ways, the board has an opportunity to look at this case afresh," said Laura Moye with Amnesty International USA, which has long denounced Davis' conviction.
A new witness who testified during a 2010 evidentiary hearing said he saw another person shoot MacPhail. Supporters hope that fact will be considered by the parole board.
"So why is it that we are willing to believe what they said in 1991, but are not willing to believe what they have to say today," Moye said. "Most of (the witnesses) have recanted or contradicted their testimony and additional testimony has come forward to implicate this alternative suspect."
MacPhail's family has steadfastly asserted that Davis was the killer, and the district attorney who prosecuted Davis has maintained his position that Davis is guilty. He does not have much confidence in witness recantations.
"I'm just disappointed so many people have been led to believe nobody has paid attention to these recantations. It is simply not the case," former Chatham County District Attorney Spencer Lawton once told CNN affiliate WTOC. "On what grounds are the recantations more believable than the testimony in court? None."
Reviewing Davis' claims of innocence last year, the U.S. District Court for the Southern District of Georgia found that Davis "vastly overstates the value of his evidence of innocence."
"Some of the evidence is not credible and would be disregarded by a reasonable juror," Judge William T. Moore wrote in a 172-page opinion. "Other evidence that Mr. Davis brought forward is too general to provide anything more than smoke and mirrors," the court found.