AP

By a vote of 8-1, the Supreme Court of Mississippi this afternoon halted the scheduled execution of Willie Manning just hours before the convicted murderer was to be put to death by lethal injection at the Parchman prison in Sunflower. In their brief order, which you can read for yourself here, the justices did not give any reason for blocking the execution, and it is unclear at this time exactly how the case will proceed from here. (For The Atlantic's coverage of the case, please see the "More On" box below)

Manning, who is black, was convicted in 1994 for the murder of two white university students in 1992. He has maintained his innocence ever since, amid troublesome (and growing) questions about the accuracy and reliability of the evidence on which his conviction and death sentence are based. Manning's long-ago trial was marked by racial bias in jury selection, for example, and a jailhouse informant, who incriminated Manning in 1994, has since sought to recant his trial testimony.

But the Mississippi court's order Tuesday is likely based upon the scientific evidence that was and was not introduced at trial. Manning's attorneys have long argued that state officials should test DNA and fingerprint evidence from the crime scene -- evidence that has never been tested and that would either incriminate Manning definitively or perhaps identify someone else who may have committed the crimes. The state has consistently refused to undertake this testing even though the FBI has offered to do it, and Mississippi has a remarkable recent record of exonerating criminal defendants in such a fashion.

As a matter of law, the absence of this testing from a shaky case like this was likely enough to warrant a stay of Manning's execution. But the state's refusal to test its DNA evidence was made even more pronounced over the past few days by the intervention of federal officials. Since May 2, the Justice Department has sent three letters to the attorneys in the case announcing that the feds now are backing away from the "ballistics" and "hair fiber" testimony their so-called "expert" testified about at Manning's trial. State prosecutors heavily relied on that now-discredited evidence at trial -- as have state court judges ever since -- as proof that Manning's conviction was secure enough to warrant his execution.