“Las Vegas Bloodbath” - Full 1989 Slasher Shlock-A-Rama!

After a successful business deal in Sacramento, Sam Butler returns to his Las Vegas home, and stumbles onto his pregnant wife, Ruth, in bed with a sheriff's deputy. Whipped into a homicidal rage, Sam grabs the deputy's discarded gun, and uses it to shoot him and Ruth. After cutting Ruth's head off, Sam leaves the house with it, and picks up a prostitute named Tina. Taking Tina to the back of a motel, Sam ties her up and stabs her in the jaw, then rips one of her legs off by tying it to the back of his car.
Sam proceeds to shoot a bartender in the head, and follow a car advertising the Beautiful Lady Oil Wrestlers to an apartment complex, where he uses a shovel to crush the head of a gardener. Inside the apartment, the oil wrestlers are holding a baby shower for one of their members, Barbara, who is the first to be killed when Sam breaks in, having her unborn child cut out after Sam unsuccessfully attempts to rape her. Sam goes on to murder the other five wrestlers (as well as a man who tries to come to their aid) with various weapons, including a knife, a drill, a hammer, a gun, and his bare hands, topping the massacre off by beheading a visiting Jehovah's Witness.
Hours later, a police officer arrives, and finds Sam bathing in blood and body parts. Sam shoots the officer, and glares at the camera as the song "Las Vegas Blood Bath" plays.