Patrick David Mackay was born in Dartford on September 25, 1952, to a violent alcoholic father who died when Mackay was ten. He was assessed repeatedly through childhood, killed animals, set fires, attacked his mother and sisters, and was described by one psychiatrist as a cold psychopathic killer who was likely to commit murder. He was admitted to Moss Side special hospital as a teenager and released in 1972.
In February 1974 he killed Isabella Griffiths, an eighty-seven-year-old woman in Chelsea, strangling her and leaving a knife in her body. In March 1975 he killed Adele Price, an eighty-nine-year-old widow in Kensington. Both were burglaries that turned into killings.
On March 21, 1975, he went to Shorne in Kent to see Father Anthony Crean, a Catholic priest who had befriended him and whom he had previously robbed. He attacked Crean with an axe and a knife in the priest's own bathroom and left him in the bath. He was arrested days later.
He confessed to eleven killings and later retracted most of them, and only three were pursued. In November 1975 the Crown accepted pleas of manslaughter on grounds of diminished responsibility on all three, and he was sentenced to life. He has been refused parole repeatedly, most recently in 2023. Home Office and NHS reviews of the case examined how a man with his file had been discharged, and it has been cited ever since in arguments about the release of patients from secure hospitals.