ALGONA, Iowa (AP) — A northern Iowa man accused of stabbing to death his live-in girlfriend has pleaded not guilty. Kossuth County District Court records show 45-year-old Chad Dietrick entered a written plea Friday to a charge of first-degree murder. His trial is scheduled to begin May 15. The records say deputies and medics sent March 3 to handle a domestic dispute found 38-year-old Krista Hesebeck had died at the home she and Dietrick shared in Lakota. He was found at his parents’ Lakota home. The records say he told deputies that he’d stabbed Hesebeck, who had also lived in Atlantic prior to moving to Lakota.