A prison inmate who was serving a 50-year sentence for a Washington County murder conviction died Tuesday.

Eighty-one year-old James Dean Blum was pronounced dead due to natural causes at 7:58 a.m. at the University of Iowa Hospitals and Clinics, according to the Iowa Department of Corrections. Blum was serving his sentence at the Iowa Medical and Classification Center in Coralville for the crime of second degree murder. His sentence began on February 22nd, 2011, after being convicted for smothering his wife Patricia in their home in 2010.