Updated

Arizona authorities said Monday they discovered the body of a woman believed to be the missing mother of a girl found dead in Louisiana.

The possible remains of Suellen Roberts, 31, were found in a remote area off Interstate 40 in northwestern Arizona, according to the Yavapai County Sheriff's Office.

Thomas Steven Sanders was arrested in Mississippi on Sunday in the kidnapping of Roberts' daughter, 12-year-old Lexis Roberts. The girl's skeleton was found by hunters last month in Louisiana.

Authorities said they were trying to determine if Thomas is linked to Suellen Roberts' disappearance.

Federal investigators provided the Yavapai sheriff's office with information on the likely whereabouts of the woman's body, authorities said.

Sanders had met Roberts and her daughter a few months ago. The trio had been spotted at a drive-thru wildlife park in Williams, Ariz., and at the Grand Canyon over Labor Day weekend, authorities said.

Roberts and her daughter were reported missing from the Las Vegas area in September.

Sanders had been declared legally dead 16 years ago.

Court documents show Sanders abandoned his family in 1987 and was declared dead by a Mississippi court in 1994. He kept his true identity secret for years despite being arrested several times.