A “predatory paedophile” who has admitted a string of offences against young boys had been a babysitter who befriended parents before abusing their children.
Paul Farrell worked as a Great Ormond Street Hospital (GOSH) porter and also abused two of his eight victims there.
He can be pictured for the first time since admitting 69 offences which occurred over more than three decades.
On Friday a judge at Wood Green Crown Court lifted restrictions which had prevented Farrell’s image being published as well as details of where some of the offending is said to have occurred within the hospital.
The 55-year-old had been a lodger or babysat at the homes of his victims’ families, and befriended their parents before abusing the children at different addresses in London, the Metropolitan Police said.
Given the “predatory nature” of his offending over a lengthy period of time, police have warned “there is a very real possibility that Farrell has abused other children” and are urging any further victims to contact the Met.
At Friday’s hearing prosecutor Paul Douglass said many of the counts were “multi-incident”, adding: “So we are looking at several hundred discrete acts of sexual abuse over a period of 35 years against boys aged between five or six and 16.”
Farrell did not target children at the hospital, where he worked between 1994 and 2020, and Mr Douglass made clear it is not a case of patients at the hospital being abused.
He said: “Offences against two of the victims happened in Great Ormond Street, in the linen room, which is where the defendant was based for a large period of his employment there.
“He had a key for it and he locked the door and abused two boys in the linen room.”
A spokeswoman for GOSH said they were “deeply sorry that he was able to abuse his position and use our hospital to commit some of his offences”.
David Osborne, acting for Mr Farrell, said he accepted his client, who was not present for Friday’s case management hearing, will receive either a life sentence or an extended sentence.
Farrell’s offences include indecent assault of a boy aged between five and seven between April 1985 and April 1987.
He has also admitted 12 charges of indecent assault against another boy from 1992 to 1998, when he was aged between six and 11.
Five counts of indecency with a child in relation to the same alleged victim over the same period, for which Farrell had been expected to face trial, were left to lie on file.
Farrell has previously pleaded guilty to a series of charges relating to six other complainants, none of whom can be named for legal reasons, who are now aged between eight and 43.
The offences, carried out between 1985 and 2020, include attempted rape, sexual assault of a child under 13 and making indecent photographs of children.
A further 20 charges had already been left to lie on file.
Farrell’s sentencing will take place at the same court on May 21 and 24 and Judge Noel Lucas QC ordered that he must appear in person.
Jane Ndeti, from the Crown Prosecution Service, said Farrell had carried out an “appalling campaign of sexual abuse” and branded him a “a prolific sex attacker who presented himself as a loving family man with a stable job in London’s biggest children’s hospital”.
Detective Superintendent Dave Courcha, from the Met, said: “Farrell was extremely calculating and devious in his targeting of children – he lodged at the homes of accommodating families and won their trust, only to abuse their children under their noses over a prolonged period.
“Most of the victims lived with the trauma of what they were subjected to for decades, with two victims waiting more than 30 years before feeling ready to come forward to police.”
Detective Sergeant Jules Manock, from the safeguarding team who led the investigation, paid tribute to the “incredible bravery” of the survivors in coming forward.
She added: “The accounts they gave to police of the abuse they suffered at the hand of Paul Farrell, and how their childhoods were stolen from them, were nothing short of harrowing, and today’s result means a predatory paedophile is now in custody where he can’t harm any more children.”
The GOSH spokeswoman said Farrell’s actions “are in direct contrast to everything we stand for as a children’s hospital”.
She added: “We know that the crimes he committed and his association with the hospital may cause alarm and distress among our patients, their families and our wider hospital community.
“We would like to reiterate what has been said in court; that Paul Farrell did not target children at GOSH.
“We urge anyone who has concerns about this case to call the helpline that we have set up with the NSPCC on 0800 101 996.”