Patrick Friendly is the killer of his brother, Caleb Friendly, a fellow expatriate of the Church of the True Path cult. Caleb was planning to lure Michelle, another escapee and Patrick's love interest, directly back to cult founder Wyatt Landon, so Caleb killed him to stop him.
Patrick was found guilty and imprisoned, but the severity of the charges and his sentencing were never known. (L&O: "Lost Boys")