(Moses Lake, WA) -- A man accused of killing and sexually assaulting a woman in Moses Lake pleaded not guilty to charges. Investigators say 28-year-old Juan Gastelum raped and murdered 30-year-old Yanira Cedillos back in March. Authorities found the victim's body in a remote area in Walla Walla County two months later. Investigators believe Castelum picked up Cedillos on the night of her birthday and then killed her in her apartment.