Arthur Mitchell’s Trinity killings all follow a ritual pattern, recreating the tragic events of his own childhood over and over again in a series of grisly killings: the abduction and murder of a 10-year-old boy, the murder of a woman by forcing her to leap off a building, and bludgeoning a man to death as part of a yearly ritual. In spite of this, Mitchell maintains a respectable home life, appearing to be a loving father and husband and active member of his church and as part of a group called Four Walls One Heart that helps construct homes for the homeless in a manner similar to Habitat for Humanity.
The concept of the Trinity Killer was inspired by real-life serial killer Dennis Rader. Rader, also known as the BTK (Bind, Torture, Kill) Killer, lived a quiet life with his wife and children for years and was a dedicated member of the Christ Lutheran Church, all the while taunting the police with letters detailing his crimes (via NBC News). Eventually, Rader was caught when he sent a file with a Christ Lutheran Church document included. On “Dexter,” a similar slip-up on Mitchell’s part allows the Miami police to determine a link between Mitchell’s Four Walls One Heart housing units and the Trinity Killer.