A mother was on the phone to her son when he was attacked by a stranger who stabbed him to death with a pair of scissors, a court has heard.
IT analyst Paul Smith, 28, was attacked by George McAdam near Princes Street Gardens in Edinburgh in May.
A court heard McAdam had only been freed from prison two weeks earlier.
Prosecutors accepted his not guilty plea on the basis he “lacked criminal responsibility” at the time of the attack due to a mental disorder.
McAdam was formally acquitted at the High Court in Glasgow.
The court heard Mr Smith had been returning to work at Edinburgh University when he was attacked by McAdam and stabbed 32 times.
Prosecutor Ashley Edwards QC said: “He was still chatting to his mother by telephone.
“She then describes hearing ‘a horrific scream’. She heard her son saying: ‘Help me… need police, need police.”
Margaret immediately yelled to her husband Ian to dial 999.
But Mr Smith did not survive the attack, which happened close to Edinburgh Castle.
The court heard McAdam, 40, initially fled the scene but was rugby tackled by a passer-by in a nearby car park.
McAdam, who had faced a murder charge, will remain at the State Hospital at Carstairs.
The court heard he had been sleeping rough in Edinburgh at the time.
‘Stayed on the phone’
McAdam had a lengthy list of convictions in Scotland and England, including for possession of a knife and assault.
He had been freed from HMP Edinburgh on 15 May, just over a fortnight before the fatal attack.
Mr Smith, of Balerno, was attacked at about 13:45 on 30 May, after visiting a KFC restaurant for lunch.
Prosecutor, Ms Edwards told the court: “His mum immediately told her husband to call police as their son needed help.
“She stayed on the phone to her son.”
The court heard McAdam had grabbed Mr Smith, who tried to defend himself.
‘He’s stabbed me’
Ms Edwards said: “McAdam repeatedly stabbed him in the chest area.
“Paul Smith shouted ‘he’s stabbed me’ and fell to the ground.”
McAdam then dragged Mr Smith down a steep embankment while continuing the attack.
The court heard he knelt beside his victim and struck him multiple times on the body and neck.
Members of the public heard Mr Smith’s cries for help but the court was told McAdam appeared “oblivious” to a crowd that was gathering.
McAdam eventually ran off but was tracked to a nearby NCP car park.
Police and paramedics spent more than 30 minutes trying to save Mr Smith, but Ms Edwards added: “His injuries would not have been survivable even with medical intervention.”
The court heard McAdam was later seen by psychiatrists and was found to be suffering from paranoid schizophrenia.
Lord Turnbull ordered him to remain at Carstairs on an interim compulsion order.
The case will call again in February.