A documentary about one of Britain's most prolific serial killers is now streaming on Prime Video.

Confessions of a Psycho Killer tells the story of Patrick Mackay, who grew up around Dartford and Gravesend, and confessed to brutally murdering 11 people.

Mackay was jailed for life with a minimum of 20 years in 1975 for three killings but originally owned up to eight more before retracting his admission.

He carried out his killing spree in the 1970s – brutally murdering elderly women in London and a priest.

The killer was just 23 when he was jailed for stabbing and strangling pensioner Isabella Griffiths, 87, in Belgravia, central London, in 1974 and 89-year-old Adele Price the following year.

It was also in 1975 when Father Crean, 64, was found hacked to death and left in a blood-soaked bathtub in Shorne.

The other eight attacks, which Mackay initially admitted, remain unsolved and a judge has said will stay on file.

Dubbed "Britain’s forgotten serial killer", the 70-year-old, who now goes by David Groves, is the country's longest-serving prisoner.

The 90-minute film arrived on Amazon Prime Video on February 1 and features accounts from former Kent Police officers, forensic psychologists, and criminologists.

A couple of neighbours have also shared their recollections on the documentary of the Mackay family when they moved to Frobisher Way, in Gravesend.

A segment of the production features Pat Paulson, who lived just a couple of doors away from Patrick, his mum and two sisters.

She described Mackay as "a slightly strange looking young man, very skinny, and there was something about his face, his eyes in particular, that just made you feel a little uncomfortable about him."

Di Dooley also lived nearby and said most neighbours and children were in fear of Mackay.

She recalls her mother telling her to keep away from the boy "because of the way he was", describing him as "very imposing" and "like a dark shadow in the street".

Mackay is expected to go before a parole board in April after applying for an early release.

He had been set for a hearing last September but, like his previous bids, it got rejected.

A source told The Mirror that this time, Mackay believes he has the backing of prison staff and psychiatrists for his model behaviour behind bars.

The killer, who is in an open prison, will claim he is no threat to society.