Killer, 94, who smothered wife found dead in custody

Donald Morley, 94, was found guilty and sentenced over the domestic violence-related murder of Jean Morley in April this year.

However, because he was terminally ill with skin cancer and dementia, Morley had been transferred to medical facility.

"At the time of his death, he was a sentenced prisoner," ACT Policing said in a statement on July 14.

Police said he was found dead on Friday, July 12, at Clare Holland House, located on the shores of Lake Burley Griffin in Barton.

He was arrested almost one year ago, on July 31, after a nurse had discovered the body of his 92-year-old wife on a scheduled visit.

Morley picked up a pillow and suffocated his wife of 69 years in an act of "non-voluntary mercy killing", his lawyer had previously told the ACT Supreme Court.

He used to call the victim "my darling" and used this pet name in a note found by the aged care worker.

"Please don't call this murder suicide. After 69 years married we were both afraid of the future ... this wasn't easy for me especially my darling," the note read.

However, Justice David Mossop ruled it was a case of domestic violence and sentenced Morley to imprisonment while he sat in hospice.

"Murder remains murder," the judge had said.

An ACT Policing spokesperson said there were no suspicious circumstances surrounding his death, and police would submit a report to the coroner.