A man accused of stabbing four people on an Amtrak train in southwestern Michigan has been found mentally incompetent for trial.

Berrien County Judge Dennis Wiley ruled Monday that 44-year-old Michael D. Williams lacks the capacity to aid in his defense to attempted murder charges. He'll undergo mental health care and be re-evaluated periodically to see if his condition has changed.

Family members say Williams has struggled with delusions and paranoia.

Police say the Saginaw man told them he started the attack Dec. 5 after seeing a man on the train turn into a demon. The train began in Chicago and was bound for Port Huron.

Investigators say Williams stabbed a conductor and three other people when the train stopped in Niles, about 10 miles north of South Bend, Indiana.