On March 21, 1975, Father Anthony Crean was killed in a frenzied axe attack in his home at Shorne, in Kent, not far from where Patrick Mackay's mother lived. The axe was left at the scene, and several witnesses had seen Mackay in the area. One of the investigating officers remembered an incident months earlier: Mackay had befriended the priest and then broken into his house and stolen a check for £30. Crean had tried to talk the police out of prosecuting, but Mackay was convicted, ordered to pay compensation and never did, and the two fell out. The police arrested Mackay, and he quickly admitted killing Crean. His fingerprints matched those at the scene of the murder of Adele Price in Chelsea eleven days before.
Mackay was born at Park Royal Hospital in London on September 25, 1952, to Harold Mackay, a Scottish accountant, and Marion Mackay, of Creole descent from British Guiana, and grew up in Dartford with two younger sisters. His father beat him. At school he bullied younger children, a classmate remembered him as "like a little terrorist," and he tore the wings off birds. When he was ten his father died of a heart attack on the way to work; his last words to his son were "Remember to be good." Mackay told people his father was still alive and carried his photograph. He took on the role of father figure by beating his mother and sisters, and after the family moved to Gravesend the police were called to the house as often as four times a week. He tried to kill a younger boy. At fifteen a psychiatrist, Leonard Carr, diagnosed him as a psychopath who would grow into a "cold, psychopathic killer," and a teacher called him "a potential murderer of women." He was removed from home eighteen times between twelve and twenty-two, and in October 1968 was committed to Moss Side Hospital in Liverpool, which released him in 1972.
In London he became fascinated with Nazism, called himself Franklin Bollvolt the First, filled his flat with memorabilia and drank and took drugs. Chelsea and Knightsbridge saw a rise in muggings and robberies of elderly women by a man who befriended them and got into their homes. On February 14, 1974, he beat, strangled and stabbed Isabella Griffith, eighty-four, in her home in Chelsea. On March 10, 1975, Adele Price let him into her Chelsea home when he asked for a glass of water, and he killed her; her granddaughter, coming home, passed him as he left. After his arrest jewelry and silver fountain pens from robberies in Chelsea and Belgravia were found at his home, and he took detectives to Clapham, where he said he had thrown away the knife.
On remand at Brixton, other prisoners told detectives he had spoken of six more killings, and his descriptions matched unsolved cases: the German au pair Heidi Mnilk, seventeen, stabbed on a train and thrown out near Catford on July 9, 1973; Mary Hynes, in Kentish Town on July 20, 1973; a homeless man thrown off a bridge into the Thames in January 1974; Stephanie Britton, fifty-seven, and her grandson Christopher Martin, four, on January 12, 1974; and Frank Goodman, beaten to death with a metal bar over a pack of cigarettes on June 13, 1974, a bar his landlords recognized. He was also said to have confessed to killing Sarah Rodmell, ninety-two, in Hackney on December 23, 1974, and was questioned about Ivy Davies, a café owner in Southend killed in February 1975, though he did not recognize her café. He later denied all but four, Griffith, Price, Crean and the homeless man, who was never identified.
At his trial in November 1975 he pleaded guilty to the manslaughter of Isabella Griffith, Adele Price and Father Crean on the ground of diminished responsibility; his defense had argued insanity, but the medical experts concluded he was a psychopath, a personality disorder rather than a mental illness. The Goodman and Hynes cases were left to lie on file. He was sentenced to life with a minimum of twenty years. In a 1989 BBC documentary, held in a special unit at Hull for some of the country's most dangerous prisoners, he denied being a psychopath.
He became eligible for release in 1995 and has been refused it repeatedly. In 2017 he was moved to an open prison with day release. The Dartford MP Gareth Johnson raised the prospect of his release in Parliament in 2019. A 2020 parole hearing was postponed while police looked again at the killings he was suspected of, without finding enough evidence to charge him, and in May 2021 the board refused release but let him stay in open conditions. In 2022 his case was referred to the board again. Ivy Davies's son, unable to give an impact statement because Mackay was never convicted of her death, said: "Everyone knows he did more. He hasn't shown any remorse." By 2025 Mackay had been in custody for fifty years.