Mark Hacking (search) has been arrested for the murder of his pregnant wife, Lori Hacking, Salt Lake City police said Monday. Authorities haven't found Lori Hacking's (search) body, detectives said in a news conference. The arrest came after the investigation into the young woman's disappearance took a grim turn, as authorities redirected their attention to a landfill and her relatives asked volunteers to stop looking for her in response to new information from the woman's husband.