Troy Anthony Davis was convicted of the 1989 shooting death of an off-duty Savannah, Ga., police officer responding to the beating of a homeless man in a parking lot. Since his 1991 trial, seven of nine prosecution witnesses have recanted their testimony and other witnesses have implicated someone else in the killing, The Atlanta Journal-Constitution said.
The order was unusual in that the court usually does not make a major decision during its summer recess, scotusblog.com reported. It is also unusual in that the court usually does not issue an opinion justifying its decision -- Justice John Paul Stevens wrote the opinion and was joined by the majority with the exception of Justice Sonia Sotomayor, who is new on the court.
Justice Antonin Scalia wrote a dissent and was joined by Justice Clarence Thomas.
Attorneys for Davis filed an original writ of habeas corpus -- a request that the justices review the constitutionality of his detention -- directly with the Supreme Court. Such requests make an end run around federal law limiting the scope of death penalty appeals.
"Today, without explanation and without any meaningful guidance, this (Supreme) Court sends the U.S. District Court ... on a fool's errand," Scalia wrote in dissent. "That court is directed to consider evidence of actual innocence which has been reviewed and rejected at least three times. ... I truly do not see how the District Court can discern what is expected of it."
A number of officials have taken up the prisoner's cause, including Pope Benedict XVI.