Paul Smith was on his lunch break when George McAdam stabbed him 32 times with a pair of scissors near Edinburgh Castle.
Killer McAdam's not guilty plea to a murder charge was accepted because he was 'not criminally responsible' due to a mental health disorder.
He could however spend the rest of his life living in Scotland’s most secure medical facilities.
McAdam is currently under lock and key at Carstairs, the State Hospital, which was originally constructed to hold the most dangerous mentally ill men and women in Scotland and Northern Ireland.
The State Hospital, set in the Lanarkshire countryside, has held some of the country’s most infamous killers, including a number of serial killers.
History of mental illness
McAdam has a long history of mental illness and has been a drifter for most of his adult life.
He grew up in Washington, Tyne and Wear, and was no stranger to the local courts.
He has convictions for public order offences, theft, assault and possession of a knife.
During his years of homelessness and the downward spiral of his mental health, he has committed offences in Glasgow, Skye and Edinburgh.
Freed from custody weeks before killing
McAdam had been freed from custody at HMP Saughton on May 15, just two weeks before he killed innocent Paul Smith.
He had appeared at Edinburgh Sheriff Court to pled guilty to a minor offence and was admonished - set free and back on the Capital’s streets.
It is believed McAdam had been sleeping rough and had awoken shortly before coming across Paul as he returned from his lunch break.
Psychiatrists at Carstairs will spend weeks working with McAdam after he was sent to their care under an interim compulsion order. It is expected McAdam will be ordered to be detained at the hospital until he is no longer regarded as a threat to members of the public or himself.
McAdam claimed he did not know he had killed Paul, despite making one statement admitting the attack.
He asked detectives: “How is that guy anyway? I tried to help him and got chased. I tried to save someone’s life and everyone’s calling me a murderer.”