Top 10 Most Dangerous Prisoners Ever Held In Full Sutton Prison

10 - Sean O'Callaghan

Described as one of the Irish Government's most important spies operating within the Provisional IRA during the troubles of the late 20th centaury, Sean O'Callaghan was well known within the IRA organisation.

Having left the IRA in the mid-1980's, he voluntarily surrendered to British prosecution due to allegations he had engaged in as an IRA gunman in the 1970s.

Presenting himself to the officer on duty at the desk of a police station in Tunbridge Wells, O'Callaghan confessed to the murder of Ultra Defence Regiment member Eva Martin and the murder of D.I. Peter Flanagan during the mid-1970s.

He was offered witness protection by the Royal Ulster Constabulary but refused this and was later prosecuted for the two murders and 40 other crimes, later pleading guilty to every charge.

Having been found guilty he was jailed for a total of 539 years, spending much of his prison time in Northern Ireland and serving a portion of his sentence at Full Sutton.

Released after being granted the Royal Prerogative of Mercy by Queen Elizabeth II in 1996, he had his story published in The Sunday Times while still locked up.

He went on to live a quiet life in London and passed away after suffering a heart attack at the age of 63 while in a swimming pool in Kingston, Jamaica.

9 - David Mulcahy

Presented as the chief perpetrator by the prosecution at court, David Mulcahy, along with his accomplice John Francis Duffy, became known as one half of "the railway killers".

Responsible for attacking numerous women and children at railway stations in southern England during the 1980s, Mulcahy was deemed to have been the one to start the killing frenzy.

Duffy was arrested, tried and convicted first, later admitting in police interviews that Mulcahy had actually been the ring leader of the two.

DNA tests conclusively proved his involvement in the killings and a search of his home revealed further involvement.

Mulcahy was convicted of three counts of murder and seven counts of rape and was given three life sentences, with a 30-year recommendation, and 24 years imprisonment for each full rape offence.

He is never expected to leave prison.

8 - Curtis Warren

Working as a nightclub doorman, Warren began to learn the ways of the drugs trade, gaining in-depth knowledge and inside education from patrons.

He travelled to Venezuela in 1991, and along with businessman Brian Charrington, met with members of the Cali Cartel and smuggled cocaine in steel boxes, concealed in lead ingots.

The first shipment passed customs, however the second, which had a tip off from Dutch police was caught and those involved were arrested.

The court case collapsed after it was revealed one of the men was a police informant, leading to charges being dropped.

Later arrested in the Netherlands with a £125 million stash of guns, ammunition, drugs and hand grenades, he was sentenced to 12 years in a maximum security prison.

He was later found guilty of conspiracy to smuggle cannabis and sentenced to 13 years imprisonment, extended for 10 years when he failed to pay a £198m confiscation order, but was released in 2022 and has now dissapeared.

7 - Danilo Restivo

Born in Sicily, Restivo grew up in the city of Potenza, in the Basilicata region of Southern Italy.

Often attempting to arrange dates with women while claiming to have a present for them, Restivo would often harass those who rejected him with constant phone calls.

He was well known to police in the local area and a number of assaults on both women and children had been linked to him but no arrest warrant was initially granted.

He want on to Murder Elisa Claps in 1993 after she met him in a church and later attacked and killed Heather Barnett.

He was arrested, but produced a bus ticket that he claimed as an alibi and was released without charge in 2003.

In November 2006 he was rearrested and his home searched after a schoolgirl identified Restivo as the man who had cut her hair on a bus.

New techniques later revealed a bloodstained towel left at the murder scene had a DNA match for Restivo and he was later charged with the murders of both women.

The case drew international attention after he was found guilty of all the charges againsed him and was handed a whole life order by the presiding judge.

This was reduced to 40-years on appeal, however he was told he would probably never be released from prison with an earliest release date of 2055.

Did You Know?

Full Sutton Prison was once considered to be one of the most dangerous in the United Kingdom with multiple attacks causing staff to be taken hostage and one rampaging prisoner causing £15,000 in damage.

6 - Darren Osborne

Nicknamed The Finsbury Park terrorist, Darren Osborne was sentenced to 43 years behind bars after being jailed for life for his murderous attack on Muslims in London.

Sentenced to a multitude of concurrent-life terms for the murder of Makram Ali and the attempted murders of other people, Osborne was described as being rapidly radicalised over the internet.

Osbourne had attacked a group of people outside Finsbury Park Mosque in 2017, driving a van at high speed into a large group of people in Muslim dress.

Having had prior convictions for violence, he was also convicted of burglary, property crimes and possession of drugs.

His earliest release date is scheduled for 2061 although it is thought he may never be released.

5 - Omar Khyam

Trained in bomb-making at the Malakand training camp in Pakistan in 2001 or 2002, Khyam was later exposed as the ringleader of a plot to explode a fertilizer bomb in the greater London area.

Described by the trial judge as "ruthless and devious", he grew up in a largely secular Muslim household.

Becoming interested in both religion and politics as a teenager, he became involved with a militant political group and often attended sermons on Islamic Jihad.

He attended a mujahideen training camp in Pakistan, took out a $16,000 loan and met several high profile members of the al-Qaeda network.

After attempting to build the bomb, which the security services were well aware of, he was arrested and put on trial at the Old Baily in London.

Found guilty alongside four other men, he received a life sentence, being told there was no guarantee he would ever be released.

4 - Steven Grieveson

Considered to be one of Britain's most evil killers, Steven Grieveson eventually became known as the Sunderland Strangler.

Grieveson murdered 18-year-old Thomas Kelly in 1993 and initially got away with the killing before going on to attack and kill four other people.

He was initially arrested after a burglary at a property where one of the bodies was found and later charged with the three murders in November 1995.

Facing a six-week trial in 1996 where he was handed three life sentences for murder, he was ordered to serve a minimum of 35 years in prison.

He was re-arrested at Full Sutton in November 2000 over a fourth murder of 14-year-old Simon Martin.

He was convicted of Simon Martin's murder on 24 October 2013 following a trial at Newcastle Crown Court.

Arrested again in 2014, this time over the murder of a seven-year-old girl named Nikki Allan, her neighbor, who had confessed was found to have been questioned by police using oppressive methods and was released.

Now serving four life sentences, it is unknown if he will ever be released and may yet be subject to a whole-life order.

3 - John Cannan

Former car salesman Cannan once boasted to have had 100 one-night stands and was said to be charming when he met potential victims on nights out.

Cannan, however was anything but charming, and began his life of crime at the age of 14, after indecently assaulting a woman in a phone box in Erdington.

Slipping into alcoholism and spending much of his time frequenting bars and nightclubs to avoid family life, he was later the suspect in a number of attacks on women that became known as "The House For Sale Rapist"

After leaving his first wife, Cannan attacked his then girlfriend Sharon Major, whom he later told he meant to kill.

After robbing a petrol station kiosk in February 1981 and holding several people at knifepoint he spent five years in various prisons around London.

He went on to murder Shirley Banks and is suspected in the murders of both Sandra Court and Suzy Lamplugh.

Already convicted of Indecent assault, rape, abduction and attempted kidnap, Cannan actually became eligible for parole in 2022, however it is up to the parole board if he is ever released.

2 - Jeremy Bamber

Currently still protesting his innocence, Jeremy Bamber was convicted of shooting dead his adoptive parents, sister and six-year-old twin nephews at the family farmhouse in Essex.

He was revealed to have planted evidence to try and frame his sister, a known schizophrenic to look like she had killed herself in a murder-suicide.

It was revealed that motive for the killings stemmed from the claiming of a six-figure inheritance and in 2002 he was told that he would never be released.

Fears as to whether Bamber has been a victim of a miscarriage of justice have been raised, however as of 2021, no investigation into his sentence has been issued.

A considerable legal challenge to his guilty verdict has been launched including an innocence campaign website and a number of high-profile supporters that include leading barrister's and human rights campaigner's.

1 - Dale Cregan

Becoming a drug dealer before he had even left high school, Dale Cregan claimed to have lost his left eye during a fight in Thailand.

His murderous rampage on the streets of Manchester began when he shot dead Mark Short, 23, in the Cotton Tree pub in Droylsden.

During this incident he attempted to kill three other men, before he went on to kill Mark's father David Short.

Still on the run by the 18th September 2012, Cregan made a hoax emergency call to the police, resulting in two officers being dispatched to his reported location.

Cregan attacked Police Constables Nicola Hughes and Fiona Bone moments after they had arrived, shooting both of them and throwing an M75 hand grenade.

Handing himself into police shortly afterwards, his trial, which began on 4 February 2013 was held at Preston Crown Court and was guarded by many armed officers such were the charges.

Daily convoy's to court, carrying Cregan, included two prison vans, police cars, motorcycle outriders and a helicopter with costs for the trial thought to have come to £5 million pounds.

Convicted of all four murders and of three attempted murders, Cregan was handed a whole life order and served a considerable amount of this at Full Sutton before going on hunger strike.

He was later moved to Ashworth Hospital in September 2013 where he is thought to remain to this day.

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