The reason Killer Joe felt so vicious and so real was because it was. All of it: the choking, the bruises, the deep-throating of a chicken leg, the body slam into the refrigerator, Cox’s groping of Wellin through her dress as Joe attempts to seduce Dottie, Cox’s semi-erection at the beginning of Act II after Joe succeeds. “It was real,” says Darcy McGill, the costume designer, “because there was a psychopath onstage.”