A killer murdered a friend and cooked and ate part of his brain after tricking mental health staff into releasing him into the community, official reports said, AFP reported.
Peter Bryan, now 39, butchered his friend in 2004 after being released from a secure hospital in north London by inexperienced staff, said reports by health authorities on Thursday.
Bryan, who was found at his friend's flat partly naked and covered in blood, told police officers: "I ate his brains with butter. It was really nice."
Weeks later, after being placed in a high security hospital in London, Bryan killed again, throttling a fellow patient and smashing his head on the ground.
The reports into the deaths showed a list of failings by psychiatric and social services over their handling of Bryan.
The reports revealed deficiencies in care had enabled Bryan to convince staff he was coping with his condition and responding to treatment therefore allowing him more freedom.
"There was ... a systemic failure to ensure that the key professionals allocated to care for Peter Bryan in the community had the necessary experience to deal with someone with his forensic history and complex presentation," one of the reports said.
Bryan had been admitted to a secure hospital after beating a shop assistant to death with a hammer in 1993. But eight years later, mental health experts decided he could live in the community under supervision.
In 2002 he moved to the London hostel but his supervising psychiatrist had never before been responsible for a killer and his "very inexperienced" social worker had no training in mental health.
Bryan was moved from the hostel into a psychiatric ward at a centre in London after allegedly indecently assaulting a girl. But just weeks later Bryan was given permission to leave the ward temporarily.
On the day of the killing, Bryan purchased a hammer, Stanley knife and screwdriver before driving to his friend's home. Both of the victim's arms and one of his legs had been severed from his body.
Bryan was jailed for life after admitting to both murders at a hearing at London's Old Bailey in 2005.