Serial killer Geoffrey Evans died in hospital from an infection after spending more than three years in a vegetative state, an inquest heard.
Evans (68), who was being held prisoner at Arbour Hill following his conviction for his involvement in the rape and murder of two women in 1976, died at St Mary's Hospital in the Phoenix Park, Dublin, on May 20 last year.
Dublin Coroner's Court heard that Evans had suffered a stroke following a heart bypass operation at the Mater Hospital on Christmas Eve 2008, and never recovered.
He remained in the Mater under round-the-clock guard at an annual cost to the State of 900,000 until June 2010. He was then granted temporary release after being medically declared to be in a vegetative state.
He was then transferred to St Mary's Hospital in April 2011 and remained there until his death. The post-mortem found that he died as a result of sepsis due to hospital-acquired pneumonia.
The court heard that the dead man's family are UK-based and were aware that the inquest was taking place but had chosen not to attend.
Englishman Evans was one of Ireland's most notorious killers. Along with his accomplice, John Shaw, he planned on abducting and killing a woman a week, and they murdered two before being apprehended by gardai.
At the time, the two men were being sought by UK police in connection with a number of rapes.
In August 1976, they drove to Brittas Bay in Co Wicklow where they offered a lift to 23-year-old foreign exchange clerk Elizabeth Plunkett, from Ringsend in Dublin.
They took her to Castletimon Wood where they raped her repeatedly before strangling her to death.
They subsequently travelled west and in early September abducted Mary Duffy, a 24-year-old cook who was trying to arrange a lift home.
Ms Duffy was beaten and raped in the back of the car before the two men drove to Ballynahinch in Connemara, where she was tied to a tree for hours and repeatedly raped before being murdered.
Gardai arrested the men later that month when their car was identified and they confessed to the murders.
Shaw remains incarcerated at Castlerea Prison in Co Roscommon.