A teenage murderer who killed a man with a Rambo knife after being freed on bail has been detained for life and ordered to serve at least 17 years.
The 17-year-old – whose identity is protected by the law despite a media attempt to waive his anonymity – lay in wait armed with the eight-inch blade before chasing John McNab and stabbing him to death in Edinburgh.
His 22-year-old victim pleaded with the teenager as he struck him repeatedly with the knife at Great Junction Street, in the Leith area of the capital, on September 2.
The killer, who was 16 at the time, messaged a friend to boast: ‘Ran after him on the middle of Junction Street wi a big Rambo, he fell to the groon and I started stabbing f*** oot o him.’
He was in the dock for sentencing at the High Court in Dundee on Thursday having admitted the murder at a hearing last month.
The teenager also pleaded guilty to another knife attack, on March 21, 2025, at Portobello beach in Edinburgh.
He pursued a 16-year-old boy on the promenade and seriously wounded him, but was bailed on April 25 last year before going on to murder Mr McNab.
The courtroom was packed with Mr McNab’s friends and family, many of whom wept as Lord Harrower issued his sentence.
He told the teenager: ‘You have been convicted of the murder of John McNab, a young man with everything to live for, and whose loss has left an incalculable void in the lives of his family and friends. This was caught on CCTV and played in court.
‘Those present will never forget what they saw and heard. They saw John McNab being chased by you along Great Junction Street, pleading for his life as he realised he could not outrun you, and his screams as you repeatedly plunged the knife into his body.’
The judge said the teenager had initially tried to buy cannabis from a group including Mr McNab and had been angry when they tore his money up in front of him. He added: ‘You pursued the group. They locked themselves inside a flat while you remained in the area. Half an hour later you climbed into bushes.
‘You waited 40 minutes, armed and wearing a balaclava. John McNab left the flat. Following a chase he fell to the ground and as he lay there you carried out a merciless attack.
‘Afterwards you sent voice notes and messages boasting about the stabbing.’
Lord Harrower said the killer had been ‘preoccupied with violence’ and had ‘persisted with antisocial attitudes and behaviours’ since being remanded pending trial. He continued: ‘You accept the murder was pre-planned and premeditated. Violence and conflict have become normal for you.’
Mark Stewart, KC, defending, said: ‘Violence seems to be seen by him as a solution to any challenges or attacks upon his status’.
During earlier proceedings, advocate depute Michelle Brannagan told how Mr McNab had been heard saying: ‘Help me, help me, I’m dying.’
A psychiatrist diagnosed the killer as suffering autism spectrum disorder and complex post traumatic stress disorder.
After sentence was imposed a hearing took place in which the BBC and STV argued that the killer’s right to anonymity should be removed but Lord Harrower rejected the application.
He said: ‘Naming him at this stage risks reinforcing his own unhelpful self-presentation.’
Mr McNab’s mother, Lisa Petrie, told BBC Scotland News: ‘Our law needs to change. Our sale of knives need to change. Our culture needs to change.
‘I’ve already lost my child. Let’s not lose any more.’
Laura Buchan, legal director with the Crown Office and Procurator Fiscal Service, said: ‘The murder of John McNab shows the serious and tragic harm caused when someone chooses to carry and use a bladed weapon.’
