JACKSON (AP) — A Mississippi death row inmate sat Monday in a holding cell at the state prison at Parchman awaiting word on a possible reprieve from Gov. Phil Bryant or the state Supreme Court.

Willie Jerome Manning’s attorneys asked the state Supreme Court on Monday to stop his execution and allow him to seek post-conviction DNA testing of evidence from the investigation into the 1992 slayings of two college students. Manning insists DNA testing will show him innocent.

The execution is scheduled for 6 p.m. Tuesday.

The Supreme Court, in separate identical 5-4 rulings, has declined to grant Manning time for the tests and to stop his execution. The court gave the attorney general’s office until 4 p.m. to respond to Manning’s motion. Bryant spokesman Mick Bullock said Monday that the governor had not yet reached a decision.

Manning was handed two death sentences for the slayings of Jon Steckler and Tiffany Miller, whose bodies were discovered in rural Oktibbeha County on Dec. 11, 1992. Each was shot to death and Miller’s car was missing. The vehicle was found the next morning.

Prosecutors said Manning was arrested after he tried to sell some items belonging to the victims.

The FBI has offered to conduct the DNA testing after saying its microscopic analysis of evidence in the case, particularly of hair samples found in Miller’s car, contained erroneous statements. Manning’s attorneys have seized on that statement as key to seeking a stay of execution.

“This motion is compelled by the extraordinary admissions by the FBI,” wrote Manning attorney Robert S. Mink in the brief.

In its statement, the FBI says its expert should have testified that he only determined that the hair fragments exhibited traits associated with African-Americans, not that it came from an African-American.

Mink said the statement then given at Manning’s trial was false.

“The FBI’s misleading exaggeration of the hair’s probative value was just what the prosecution needed … (it) allowed the prosecutor to make the incorrect statistical argument that the hair increased the odds that Manning was the perpetrator of the crime.

“This was an invaluable, though incorrect, argument in a case built primarily on circumstantial evidence,” Mink said.

Defense attorneys have denied the DNA testing is an “11th hour” gambit as described by Attorney General Jim Hood. They said Manning has been trying to get DNA testing dating back to 2001.

Hood said the state is prepared to conduct testing any time “there is legitimate, exculpatory evidence” but “when the defense waits until the 11th hour to raise such claims, which could not possibly exonerate their client, courts are loathe to be subjected to these types of dilatory defense tactics.”

In its 5-4 ruling on April 25, the Supreme Court said there was “conclusive, overwhelming evidence of guilt” presented an Oktibbeha County jury.

The Supreme Court said the jury heard from Manning’s cousin and a prison cellmate that Manning has confessed to the slayings. The court said other witnesses testified that Manning tried to sell them items that were later shown to have been longed to Steckler and Miller.

Manning’s girlfriend testified that days before the slayings Manning had been firing a handgun at a tree behind their house, according to court records. FBI experts testified they matched bullets from the tree to those recovered from the scene of the slayings.

On Friday, the Innocence Project of Mississippi and Manning’s brother filed in Oktibbeha County a lawsuit that seeks a temporary restraining order that would prevent the destruction of evidence in the case.

Robert McDuff, a Jackson attorney who represents the Mississippi Innocence Project in the lawsuit, said the group wants to preserve the evidence for DNA and other testing.

“We’re hoping to get this evidence tested and let the truth come out,” McDuff said Sunday. “Hopefully, the governor or the courts will stay the execution so we can determine prior to the execution what the DNA shows. But even if they don’t, there are a lot of people who still want to see the evidence tested to determine once and for all who is responsible for this crime.”