A man who had spent three decades on Nebraska's death row for the 1985 cult killings of two people, including a 5-year-old boy, has died in prison, officials said Monday.

Michael Ryan died around 5:45 p.m. Sunday at the Tecumseh State Correctional Institutional in southeast Nebraska, the Nebraska Department of Correctional Services said in a news release Monday. Tecumseh prison spokeswoman Jessica Houseman did not have a cause of death but said an autopsy would be performed.

At a hearing in March about legislation to repeal the state's death penalty, state Sen. Ernie Chambers said Ryan had terminal brain cancer. Houseman would say only that Ryan was being treated for a long-term medical condition.

Ryan was convicted in the torture and killing of 26-year-old James Thimm at a southeast Nebraska farm near Rulo, where Ryan led a cult, and in the beating death of Luke Stice, the 5-year-old son of a cult member. Ryan has been on death row since Sept. 12, 1985.

Over three days, Thimm was beaten, sexually abused, shot, stomped and partially skinned while still alive. His fingertips had been shot off on one hand. Ryan told his followers that he heard the voice of God.

Ryan's son, Dennis Ryan, and cult member Timothy Haverkamp were sentenced to life in prison for second-degree murder in Thimm's death. Authorities said Dennis Ryan delivered the gunshot that killed Thimm after a month of torture.

The younger Ryan was later released from prison after winning a new trial and being convicted of the lesser charge of manslaughter. Haverkamp was released from his prison in 2009 after serving 23 years of a 10-years-to-life sentence.