Federal prosecutors will seek the death penalty against a man who was declared dead in Mississippi in 1994 and surfaced years later as a suspect in the deaths of his Las Vegas girlfriend and her daughter.

Thomas Steven Sanders is charged in U.S. District Court in Alexandria, La., with kidnapping resulting in the death of 12-year-old Lexis Roberts. He’s also charged with using a gun during a crime that resulted in death. Both charges carry possible death sentences.

The child’s body was found by hunters in October 2010 in Catahoula Parish, La. She had been shot and her throat was cut. The body of her mother, Suellen Roberts, was found the next month in Yavapai County, Ariz.

U.S. Attorney Stephanie Finley said Wednesday in a federal court filing that the death penalty is justified in Sanders’ case and that he’s likely to commit violent acts in the future if given the opportunity.

The filing said Sanders has threatened violence against his ex-wife and stepson.

Sanders walked away from his family in Mississippi in 1987 and they didn’t hear from him for years. His parents, brother and former wife petitioned a Pike County, Miss., 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.

He surfaced as a suspect in the deaths of Lexis and Suellen Roberts. He was arrested in Gulfport, Miss., in November 2010 after a massive manhunt.

Authorities say Sanders confessed to killing the mother and daughter.

Sanders was living at a storage facility in Las Vegas when he met Suellen 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, court documents say.

They spent the night in a hotel and played in the swimming pool. 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, according to a court records based on Sanders’ alleged confession.

“Sanders then loaded Lexis, who was in hysterics over seeing her mother murdered, into the car and traveled to Louisiana,” court records said.

He then took her to a wooded area, where he shot her multiple times, according to court records. When she did not die, he cut her throat, killing her.

Sanders has pleaded not guilty. His trial is set for Jan. 14.