A Georgia man on death row for the the 1989 killing of an off-duty police officer will die tonight after being refused a last-ditch chance to prove his innocence via lie detector.
Georgia Department of Corrections has refused to elaborate on its refusal to exhaust all possibilities for 42 year-old Troy Davis
Since 1989, Davis has pleaded innocence over the killing of killing Mark MacPhail in Savannah,
Georgia in 1989. But state and federal courts have steadfastly upheld
He is scheduled to die at 7pm tonight. It is the fourth time in four years that Davis' execution has been scheduled by Georgia officials.
Davis has captured worldwide attention because of the doubt his many supporters have raised over whether he killed MacPhail, who was shot to death August 19, 1989, after coming to the aid of Larry Young, a homeless man who was pistol-whipped in a Burger King parking lot.
Prosecutors say Davis was with another man who was demanding that Mr Young give him a beer when Davis pulled out a handgun and bashed Mr Young with it. When Mr MacPhail arrived to help, they say Davis had a smirk on his face as he shot the officer to death.
Witnesses put Davis at the crime scene and identified him as the killer. Shell casings were linked to an earlier shooting that Davis was convicted of. No blood or DNA tied Davis to the crime and the weapon was never found.
Davis' attorneys say seven of nine key witnesses who testified against davis have disputed all or parts of their testimony.
And it would appear that Davis has found support in the celebrity world. Def Jam founder Russell Simmons, hip hop artist Gostface Killah, reality TV star Kim Karashian and Reverend Sharpton all tweeted their support for him.
However, Spencer Lawton, the district attorney who secured Davis' conviction in 1991, wasn't so supportive. Lawron described his embarrassment 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," Lawton said.
"The good news is we live in a civilised society where questions like this are decided based on fact in open and transparent courts of law, and not on street corners."