A life prisoner who was dubbed the Black Dog Strangler after he choked a man with his dressing gown belt killed himself with an insulin overdose in a top security jail, an inquest has found.
Philip Whiteman had spent 25 years in secure hospitals or jail when he took the fatal dose of his diabetes medication at Frankland Prison, Durham, last November.
He died three weeks later at the University Hospital of North Durham.
An inquest at Crook Civic Centre, County Durham, before a jury, concluded it was suicide.
Whiteman killed a patient at Ashworth Hospital, Liverpool, in 1990. He believed his cell mate had turned into a dog.
He was jailed for life and ordered to serve a minimum of 10 years after admitting manslaughter on the grounds of diminished responsibility.
He was treated in secure hospitals, marrying a fellow patient then a member of staff, but after he absconded from St Nicholas's Hospital, Newcastle, in January 2013 he was transferred to jail.
The 46-year-old was found unresponsive in his cell in November last year after he had taken an insulin overdose. He had left a note on his bed.
He received care from Tees, Esk and Wear Valleys NHS Foundation Trust, which provides mental health services at the prison.
A spokeswoman said: "We were reassured to hear from the coroner at the inquest that he found no evidence of failings in the care we provided to Mr Whiteman."