IOWA CITY – A man convicted of 1st Degree Murder in Polk County died Friday, at the University of Iowa Hospitals and Clinics in Iowa City. The Iowa Department of Corrections reports 54-year old Christopher Michael Phipps, Sr., died Friday morning, due to natural causes. Prior to being transferred to UIHC, he was an inmate at the Iowa State Penitentiary, where he began serving his life sentence on Oct. 7, 2010.