Mum heard son's pleas as he was stabbed with scissors
IT analyst Paul Smith died after he was stabbed 32 times in the attack during his lunch break.
A mum heard her son pleading for his life as he was brutally stabbed to death with scissors by a stranger.
Margaret Smith was on the phone with 28-year-old Paul Smith when he was suddenly attacked by George McAdam in May this year.
Mr Smith - an IT analyst at Edinburgh University - was stabbed with scissors 32 times by McAdam, who had been freed from jail only two weeks earlier.
McAdam was formally acquitted of murder on Wednesday after prosecutors accepted his not guilty plea on the basis he "lacked criminal responsibility" due to a mental disorder.
He will remain at the State Hospital at Carstairs until a hearing in February.
Mr Smith had been returning from a lunchtime break when the 40-year-old struck near Princes Street Gardens.
Prosecutor Ashley Edwards QC told the High Court in Glasgow: "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 their son didn't survive the attack close to Edinburgh Castle.
A judge heard McAdam initially fled the scene, but was rugby tackled by a brave passer-by at a nearby car park.
The court heard how McAdam had been sleeping rough in Edinburgh at the time. He had a lengthy list of convictions both here and in England including possession of a knife and assault.
He had been freed from HMP Edinburgh on May 15 - just over a fortnight before the killing.