ALEXANDRIA, La. (AP) — A Mississippi man who was once declared dead, only to resurface as a suspect in a kidnapping and killing, was sentenced to death Friday after a jury earlier convicted him of murder.

U.S. Attorney Stephanie A. Finley said federal jurors returned the sentence against 57-year-old Thomas Sanders for the 2010 kidnapping and murder of 12-year-old Lexis Roberts of Las Vegas, Nevada.

Sanders left his family in Mississippi in 1987. He was declared dead in 1994 after he had been missing for years.

Jurors on Sept. 8 convicted Sanders of kidnapping resulting in death and using a firearm in a violent crime that resulted in death.

Sanders confessed to killing the young girl and her mother, Suellen Roberts, after his arrest in Gulfport, Mississippi.

“This is a heartbreaking case,” Assistant Attorney General Leslie R. Caldwell said in a written statement. “A young girl witnessed the murder of her mother, was held captive for days, and had her life cut tragically short by a senseless, brutal murder. We hope today’s verdict will help Lexis’ family as they continue to struggle with the loss of their loved ones.”

Sanders gave law enforcement officers detailed information that led to the discovery of Suellen Roberts’ body. His description of the little girl’s killing was matched exactly by the wounds on her body.

When Sanders was arrested in Gulfport, Mississippi, in November 2010, he was driving the woman’s car. Inside were a rifle that matched the type used to shoot the daughter and a knife with her DNA on the blade.

Prosecutors have said Sanders shot Suellen Roberts on a trip that all three took to a wildlife park in Arizona, then drove Lexis Roberts to Louisiana, where he shot her four times and cut her throat. They said after visiting a wildlife refuge known as Bearizona and stopping at the Grand Canyon, the trio pulled into a remote stretch of desert off an interstate so Suellen Roberts could shoot Sanders’ .22-caliber rifle. Instead, Sanders shot the mother in the head while her daughter sat on a blanket nearby, prosecutors said.

Sanders left the body where it fell and drove Lexis Roberts over several days to northeast Louisiana, where he shot her three times in the head and once in the chest, the prosecutor said. With the girl still alive, prosecutors said Sanders then cut her throat with a knife. Two experts testified Friday that DNA from the blade of a knife found in Sanders’ possession matched DNA samples taken from Lexis Roberts’ remains.

Sanders was identified as a suspect long after he was thought dead. Sanders had left his family in Mississippi in 1987, and his relatives and ex-wife had him declared dead in 1994 after he had been missing for years.

He was not charged in Louisiana with Suellen Roberts’ death.

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