JACKSON (AP) — On paper he was deceased, legally declared dead 16 years ago. In reality, Thomas Steven Sanders had lived openly for years without anyone noticing that fact — until his weekend arrest on suspicion of kidnapping a Las Vegas girl who recently turned up dead.

Sanders was arrested Sunday at a Gulfport, Miss. truck stop after a massive nationwide manhunt and charged with kidnapping 12-year-old Lexis Roberts, whose body was found last month in Louisiana, the FBI said. The girl’s mother, 31-year-old Suellen Roberts is missing and feared dead in a bizarre case that leaves many wondering how a legally dead man can go unnoticed for so long — even after being arrested in several states under his real name.

Authorities say the answer is pretty simple, really. There’s no national death database in the United States, said James Kelly, sheriff of Catahoula Parish in central Louisiana where the girl’s skeleton was found by hunters in October.

And at age 53, Sanders wasn’t collecting Social Security, raising no red flags there. It’s not even clear if Sanders knew he was considered dead.

“Right now we have a lot more questions than we do answers,” Kelly said.

Authorities on Monday pressed Sanders for more information about the girl’s missing mother and he was cooperating with law enforcement agents, Kelly said.

Much of Sanders’ past is a mystery ever since he walked out on his family in McComb, Miss., in 1987. He drifted from state to state and didn’t buy property or establish many bills in his name — things that create a paper trail for most people, authorities said.

His wife, Candice Sanders, divorced him in 1988 for allegedly “habitual, cruel and inhuman treatment.”

Years later, Sanders’ parents, brother and ex-wife petitioned a Mississippi court to have him declared dead. That was in July 1994, apparently so his children could receive death benefits, but it’s not clear if they did. The Social Security Administration said privacy laws prohibit the agency from discussing death benefits. Kelly said he didn’t think the family received such benefits.

Sanders moved around the country using his real name, though authorities said he sometimes gave his name as Tom or Steve or the nickname “Spider.” Investigators know he lived in Mississippi, Louisiana, Tennessee, Georgia and Nevada. He worked as a laborer, a welder and a scrap metal collector.

He was arrested several times, on charges including possession of drug paraphernalia and for several traffic and motor vehicle violations in Tennessee, according to authorities. He also was sentenced to two years in Georgia for simple battery. State and federal authorities said some of the charges involved minors, but they haven’t elaborated.

In Nevada, Sanders met Roberts and her daughter Lexis a few months ago at a storage facility where Roberts kept some possessions and where Sanders worked for a time, Roberts’ mother Mary Woodburn has told The Las Vegas Review-Journal.

The trio was in Williams and Flagstaff Ariz., and the Grand Canyon National Park over the Labor Day weekend, authorities added.

Hunters found Lexis’ remains on Oct. 8. There was evidence she had been shot.

Officials said security cameras showed Sanders buying ammunition Sept. 3 at a Walmart in Las Vegas. The bullets he bought were consistent with the weapon used to kill Lexis, authorities said.

Sanders was alone when he was arrested at the Flying J Truck Stop after a nationwide manhunt, FBI spokeswoman Sheila Thorne said, declining to release further details. Kelly said Sanders wasn’t armed and didn’t put up a fight.

Louisiana authorities want to extradite Sanders to face charges there, though it’s not clear how long that could take, Kelly said.