A Mississippi man who was declared dead more than a decade before his arrest on charges of kidnapping and killing a 12-year-old girl is appealing his conviction and death sentence.

Thomas Sanders' attorneys filed a notice of appeal Monday, asking the 5th U.S. Circuit Court of Appeals to review the case.

Earlier this month, a federal judge in Louisiana rejected Sanders' bid for a new trial. Sanders' lawyers claimed a prosecutor improperly encouraged jurors to speculate on whether Sanders sexually abused the girl, Lexis Roberts, before her death.

Sanders' relatives had him declared dead in 1994. He remained missing until his 2010 arrest in Gulfport, Mississippi.

Authorities said Sanders confessed to killing Lexis Roberts and her mother, Suellen Roberts, after they took a trip to a wildlife park in Arizona.