A prosecutor asked a judge Thursday to sanction accused killer Trucko Stampley for not cooperating with a court-ordered examination to determine if he is mentally retarded.

Such a sanction would not prevent Stampley’s court-appointed attorneys from raising the issue of mental retardation at his first-degree murder trial, but it would mean the jury would not be instructed that the U.S. Supreme Court has barred the execution of the mentally retarded.

State District Judge Bonnie Jackson scheduled a sanction hearing for Oct. 19.

Stampley, 23, of Baton Rouge, is accused in a pair of double murders in the city in 2007. Prosecutors intend to seek the death penalty if he is convicted.

Prosecutor Darwin Miller said the state had asked that East Baton Rouge Parish Prison psychiatric director Robert Blanche be appointed to examine Stampley after he refused to take part in a July 1 defense-requested exam at Tulane Medical Center.

“He wouldn’t even get out of the (Sheriff’s Office) vehicle’’ that transported him to New Orleans, Miller told Jackson during a hearing in Stampley’s case Thursday.

“There was no examination,’’ Richard Goorley, one of Stampley’s attorneys, told the judge.

Miller told Jackson that Blanche made “several attempts’’ to speak with Stampley after he was returned to Parish Prison, but he refused.

Miller said afterward that when the defense raises the issue of mental retardation, which Stampley’s attorneys did in mid-2009, the state can ask for an independent examination of the defendant.

If the defendant refuses to cooperate with that exam, Louisiana law allows the trial judge to withhold the jury instruction that the mentally retarded are not eligible for the death penalty.

“We don’t agree with it (the state law), but it’s there,’’ Goorley said after the hearing.

Stampley is charged with four counts of first-degree murder in the April 2007 slayings of Marie Pedescleaux, 80, and her daughter Denise, 46; and Charles “Chick’’ Colvin III and his wife Ann Lynn Colvin, both 73.

The Pedescleauxes were found shot to death April 25, 2007, in their Crown Avenue home in Glen Oaks.

Two days later, the Colvins were discovered fatally shot in their Thibodeaux Avenue residence in Goodwood Estates.

Stampley has pleaded not guilty and not guilty by reason of insanity. A trial date has not been set.

Stampley spent more than a year at the state mental hospital after his April 2007 arrest.

State District Judge Lou Daniel, who presided over Stampley’s case for four years before disqualifying himself in April because of a death threat from Stampley, twice ruled Stampley was competent to stand trial.