Corrections-logoA 74-year-old man sentenced to life in prison for killing his girlfriend in Des Moines decades ago has died behind bars.

Elbert James Hinkle has been in prison since the fall of 1972. Hinkle shot his former girlfriend Patty Bradley seven times and tried to rape her after Bradley and her estranged husband reconciled.

Police found Hinkle in the woman’s basement, with the gun in his pocket. A jury found him guilty of first degree murder. This past Monday, Hinkle was found on a bathroom floor in the state’s maximum security prison.

Prison officials say they believe Hinkle died of natural causes, but an autopsy will be conducted.