A former Dent County sheriff’s deputy and state correctional officer has been convicted of killing his ex-girlfriend and her boyfriend. A St. Charles County jury on Thursday found Marvin Rice guilty of first-degree murder in the 2011 death of 32-year-old Annette Durham. He was also found guilty of second-degree murder in the death of 39-year-old Steven Strotkamp. The St. Louis Post-Dispatch reports prosecutors are seeking the death penalty. The sentencing phase was to begin Friday. Prosecutors say a custody dispute between Rice and Durham led to the shooting. Prosecutors say Rice went to Durham’s home outside of Salem in December 2011 to get his son and shot the two victims. He then led police on a chase that led to a shootout in Jefferson City hotel.