Viva Leroy Nash was first imprisoned for armed robbery at the age of 15

The oldest death row inmate in the US has died of natural causes aged 94.

The Arizona Department of Corrections said Viva Leroy Nash died late on Friday at the state prison in Florence.

Nash had a criminal record dating back to the 1930s, and was deaf, mostly blind, mentally ill and had dementia, his lawyer said.

He was sentenced to death in 1983, for shooting a salesman after escaping from jail. But he managed to stave off his execution with a series of appeals.

At the time of his death, state prosecutors were appealing to the Supreme Court against a federal appeals court ruling that Nash might not be mentally competent to assist in his defence.

Nash spent 25 years in jail for shooting a Connecticut policeman in 1947

Nash's lawyer, Thomas Phalen, told the Associated Press his client was born in 1915 and had grown up in southern Utah. He was first imprisoned for armed robbery at the age of 15 in Kansas, he said.

He spent 25 years in prison for shooting a Connecticut police officer in 1947.

Then in 1977, Nash was sentenced to two consecutive life sentences for robbery and murder in Salt Lake City, but escaped from a prison work crew in 1982.

That November, he went into a coin shop in Phoenix and shot an employee. He was arrested as he fled the scene, and was later sentenced to death for first-degree murder.