COPS are urgently hunting for a killer who's fled a mental health facility - as they warn he could be a "risk".
Philip Theophilou, 54, was last seen in Homerton, east London on Sunday.
Met Police are now asking for the public's help to find the killer, but urged them not to approach him.
The force said Theophilou does not have access to his medication and they worry about "the risk he may pose without it".
The now-54-year-old knifed his neighbour to death two decades ago.
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In April 2004 he lay in wait outside Simon Breed's home in Alexandra Park - before stabbing him in the chest six times with a kitchen knife.
Theophilou then left the 51-year-old to die, while he fled to Hyde Park - where he slept rough for three days before being caught.
He was found guilty of manslaughter on the grounds of diminished responsibility.
Theophilou was sent to Broadmoor special hospital without limit of time under the Mental Health Act, in November 2005.
He has been in mental health facilities ever since.
Officers understand that the 54-year-old is thought to have travelled to the Green Park area at about 11.30am on Sunday, after leaving a mental health facility in east London.
They said Theophilou was expected to return to Homerton but hadn't been seen since.
The force said in a statement: "The clothing he was wearing when he went missing was a grey jumper, blue jeans, black jacket and black jumper [as shown in picture].
"Officers and medical professionals are concerned at his lack of access to medication and the risk he may pose without it."
In 2005 doctors told the courts that Theophilou suffered from schizophrenia but had not been taking his medication at the time of the killing.
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The fatal attack came after neighbour Simon started building work on his home when he moved in in 2002.
The works caused a crack in the home next door that Theophilou shared with his parents, the court heard.
In January 2003, the killer then took to Simon's property with a meat cleaver, causing thousands of pounds worth of damage.
He was sectioned under the Mental Health Act - but released from St Ann's Hospital in August that year.
There were no problems until eight months later when Simon returned from playing at a folk club and Theophilou launched at him.
Paul Brogan, defending, said Theophilou had been discharged from hospital in 2003 in apparently "unsatisfactory circumstances".
He said at the time: "There was a failure to monitor or treat him after discharge."
