FORT WORTH, Texas (AP) — Authorities say a North Texas man charged with molesting children attending parties at a miniature-train complex he built in his yard has died after being attacked while in custody.

The Fort Worth Star-Telegram reports another inmate at the Tarrant County Jail complex was suspected in Wednesday’s death of 76-year-old Clinton Don Simpson of Keller. Sheriff’s spokesman David McClelland says Texas Rangers would investigate.

A medical examiner reports Simpson suffered blunt force head injuries and died at a Fort Worth hospital.

Simpson ran “Mr. Don’s Whistle Stop.” He was arrested in 2007 and faced more than a dozen charges of aggravated sexual assault, indecency with a child or sexual abuse.

Records show Simpson was repeatedly found incompetent to stand trial and spent time at state hospitals.