The Rev. Gerald Robinson in 1968. (courtesy

A former Toledo, Ohio, priest convicted of killing a nun in a hospital chapel before Easter 1980 died early Friday in a prison hospital.

The Rev. Gerald Robinson, 76, who was sentenced to 15 years to life for the killing of Sister Margaret Ann Pahl, 71, died at Franklin Medical Center in Columbus. He had been given last rites a month ago after he suffered a heart attack.

Robinson was convicted in 2006 for the murder in the sacristy of the former Mercy Hospital chapel where he and the victim both worked. The nun had been strangled and stabbed 31 times.

Pahl's stab wounds formed an upside-down cross. There was a smudge of blood on her forehead.

The death came after a federal judge Thursday refused a petition for compassionate release. Gov. John Kasich had earlier denied a similar plea, the Toledo Blade reported.

The Associated Press reported Robinson became a suspect after police found a sword-shaped letter opener in his desk. He admitted lying when he said someone else had confessed the murder to him. He was not arrested until 2004, based on tests investigators were able to run with technology that had not been available in 1980.

Prosecutors said Robinson was angry because Good Friday services had been cut short and he resented Pahl's domineering ways.