Tainted Blood(1993)
After a 17-year-old shoots his parents dead and then turns the gun on himself, an investigative reporter makes a disturbing discovery. The adopted boy was born to a mother who, as a teen, inexplicably murdered her parents as well. Even more alarming is the discovery that the dead boy has a twin, who may also be genetically predisposed to kill.
Directed by Matthew Patrick - With Raquel Welch, Natasha Gregson Wagner, Joan Van Ark, John Thomson, Alley Mills, Kerri Green, ...