JACKSON (AP) — Prosecutors want more time to decide whether to seek the death penalty for a legally dead Mississippi man charged with a kidnapping that resulted in the death of a 12-year-old Las Vegas girl whose body was found in Catahoula Parish.

Thomas Steven Sanders was declared dead in Mississippi in 1994. He surfaced as a suspect in the death of Lexis Roberts, whose body was found in October 2010. The body of her mother, Suellen Roberts, was found the next month in Yavapai County, Ariz.

Sanders is charged with the child’s death in U.S. District Court in Alexandria, La.

Prosecutors have asked for a 30-day extension until Aug. 1 to decide on seeking the death penalty. The motion says defense attorneys agree with the request.

U.S. District Judge Dee Drell has not yet ruled.

Authorities have said in court records that Sanders confessed to killing the mother and daughter. His attorneys, however, have filed motions to prevent that information from being presented at trial. They argue Sanders asked for a lawyer, and questioning should have stopped.

At the request of Drell, U.S. Magistrate James Kirk investigated the confession issue and in March wrote a lengthy recommendation to allow the confession at trial. Kirk’s recommendation contained some of the most graphic details to become public about the killing.

According to the judge’s recommendation and other court documents, Sanders was living at a storage facility in Las Vegas when he met Roberts. A relationship developed and they planned to take her daughter on a trip to Bearizona, a wildlife park in Arizona near the Grand Canyon, for the Labor Day weekend in 2010.

They spent the night in a hotel and played in the swimming pool, court records said. On their way back to Nevada, Sanders pulled over in the desert “ostensibly so Suellen could shoot his .22 rifle” but instead he shot her in the head, Kirk wrote in his March filing, which drew upon the confession documents.

“Sanders then loaded Lexis, who was in hysterics over seeing her mother murdered, into the car and traveled to Louisiana. He took Lexis to a wooded area and shot her in the back of the head and, when she didn’t die, he shot her twice more in the head. When she still didn’t die, he tried to shoot her through the heart. When she still didn’t die, he cut her throat, killing her,” Kirk wrote.

Sanders’ attorneys have been trying to get the confession thrown out based on the argument that questioning continued after he asked for a lawyer. Kirk disagreed, saying that Sanders only requested a lawyer to discuss certain questions: why he killed the mother and daughter, what he had been doing while in Nevada and whether he had worked for a mattress company.

Authorities in Louisiana and Arizona have said Sanders could face state charges.

Sanders walked away from his family in Mississippi in 1987 and they didn’t hear for him for years. His parents, brother and ex-wife petitioned a Pike County court in July 1994 to have him declared dead. Despite the death certificate, Sanders was able to move about easily and undetected even though he was arrested over the years, including for drug paraphernalia and a number of traffic and motor vehicle incidents, all in Tennessee. He was sentenced to two years in jail in Georgia for simple battery.

He’s being held without bond. His trial is scheduled for January.