A serial killer dubbed the Devil’s Disciple will be grilled about eight murders he initially confessed to before it is decided if he is safe enough to be freed.
Patrick Mackay, 70, has served 47 years for three killings but originally owned up to eight more – before retracting his admission.
Now he is seeking freedom – but must first convince a Parole Board hearing he was lying about the other slayings.
Felons, including high-profile murderers, are normally given one day to discuss their case – but Mackay has been granted two.
A source said: “The notoriety of Patrick Mackay and his historic ‘confessions’ to unsolved murders warrants this level of attention
Two New York cops stabbed during celebrations in Times Square“The board will look beyond Mackay’s behaviour in prison, any remorse, and will focus on his prior criminal history.
“This obviously includes the three murders he was jailed for, but there will be questions on any other crimes he committed.
“Mackay will have to convince the panel his ‘confession’ to other murders was the ramblings of a man who was mentally ill at the time.”
Mackay was jailed for life with a minimum of 20 years in 1975 after being convicted of butchering a Catholic priest and two elderly women.
He throttled and stabbed frail Isabella Griffith, 87, after befriending her in Chelsea, West London, in 1974.
The following year he strangled fellow Chelsea resident Adele Price, 89, at her home.
Days later, in Shorne, Kent, he beat Father Anthony Crean, 64, stabbed him in the neck and attacked him repeatedly with an axe, splitting the clergyman’s skull in two.
When arrested, Mackay confessed to the three slayings – plus eight more dating back to 1973, including the unsolved murder of 17-year-old German au pair Heidi Mnilk, who was stabbed and thrown off a train in South East London.
The brutal psychopath said he killed Mary Haynes, 79, in Kentish Town, West London, the next day, and also listed a homeless man, a gran and her four-year-old grandson, a shopkeeper and a 92-year-old woman as his victims.
His final admission was to the murder of cafe owner Ivy Davies, 48, in Southend, Essex, in February 1975, who was dragged downstairs with a ligature round her neck and bludgeoned with a metal bar.
Two men stabbed outside nightclub in early morning New Year's Day horror attackMackay was a patient at a nearby psychiatric facility at the time and all of the murders were committed in London and Essex, where he grew up.
He withdrew his confession to the eight killings before he faced court over the three.
Numerous parole bids have been rejected but Mackay believes he has the backing of prison staff and psychiatrists for his model behaviour in jail.
The killer, who has changed his name to David Groves, is in an open prison, and will claim he is no threat to society.
The parole panel will read hundreds of pages of evidence, including statements from probation officers, psychiatrists and psychologists before grilling Mackay at length during the April hearing.
If the board decides to release the killer, Justice Secretary Dominic Raab has the power to step in.
Ivy Davies’ son Victor, who has spent decades fighting for justice, said: “Everyone knows he killed more people, but he’s not going to come clean.
“Why would he admit it? If he does they won’t let him out.
“All this talk about him being a model prisoner and a reformed character. How can you be reformed if you can’t admit all the others?
“It doesn’t make sense to me.”
Victor said Mackay was still a dangerous man at 70, adding: “He doesn’t know how to behave in the outside world. Being a killer is all he knows.”
A Parole Board spokesman said decisions were solely focused on what risk a prisoner could represent to the public if released and if the risk was manageable in the community.
They added: “Parole reviews are undertaken thoroughly and with extreme care.
“Protecting the public is our number one priority.”