A Fort Mohave man faces at least 25 years in prison for killing his girlfriend and a scheme putting him in control of her considerable assets. A Mohave County Superior Court jury deliberated about three hours Friday before finding Louis Plunkett, 55, guilty of first degree murder, forgery and tampering with a computer. Prosecutor Doug Camacho said the evidence showed that Plunkett beat to death Marilyn Burdick, 62, and threw her fully clothed body into her backyard swimming pool in June, 2013. Plunkett, who served as his own lawyer at trial, argued unsuccessfully that Burdick was badly injured in a fall and fell into the pool herself. Sentencing is scheduled February 24 before Mohave County Superior Court Judge Rick Williams.