Teenager given life sentence for knife murder while on bail for slashing

A teenager who murdered a man with a hunting knife while on bail for a slashing has been given a life sentence with a minimum term of 17 years.

The 17-year-old chased and killed John McNab, 22, in an unprovoked attack on Great Junction Street in Leith on 2 September last year.

The fatal stabbing came four months after the youth was released on bail having been charged with a knife attack on a 16-year-old boy at Portobello Beach.

The teenager, who cannot be named because of his age, previously pleaded guilty to both attacks.

During sentencing at the High Court in Dundee, the judge, Lord Harrower, told the youth the "merciless attack" had taken the life of a young man with everything to live for.

He added that the loss had left "an incalculable void in the lives of his family and friends".

CCTV footage showed warehouse worker McNab begging for his life before the teenager stabbed him four times as he lay on the ground.

In an exclusive interview with BBC Scotland News, the victim's mother Lisa Petrie said: "As a mum, that haunts me.

"Imagine how scared he was in that moment. That'll be with me for the rest of my life."

On the night of McNab's death, some of his friends had been involved in a brief altercation with the teenager, who was struck and slapped on the face.

The youth followed the friends to a nearby flat, shouting threats, and waited outside for more than two hours before targeting McNab as he left to get a taxi.

The victim had not been involved in the earlier incident.

In the CCTV footage, McNab could be heard pleading with his attacker, saying: "Please, please don't. I haven't done anything."

He tried to run away but stumbled at a traffic island, fell to the ground and was stabbed four times.

When his friends found him lying in the road, bleeding from a fatal wound to his abdomen, he said to them: "Help me, help me, I'm dying."

Later that morning, the teenager sent threatening voice notes to one of McNab's friends, saying: "Let that be a warning to all your pals if you ever touch me again."

Prosecutors showed the footage to Lisa Petrie before the teenager pled guilty to the murder at the High Court in Edinburgh last month.

She was also shown a photograph of the hunting knife and its 20cm (8in)-long blade.

"It felt like it went through my heart, to see what killed your own child," she said.

"But at the same time it gave me a fire in my belly where I thought, these things need to change.

"Our law needs to change. Our sale of knives need to change. Our culture needs to change.

"For our younger generation, if we don't change now, we're going to be losing a lot.

"I've already lost my child. Let's not lose any more."

Since her son's death, Lisa Petrie has campaigned for stricter rules around the sale of kitchen knives, arguing that they should be given the same security packaging as bottles of spirits or removed from shelves and placed behind counters.

She has also called for tighter restrictions on the sale of knives like the blade which was used in her son's murder.

Selling such knives to under-18s is against the law. She has not been told how the teenager who murdered her son got hold of the weapon.

The care support worker has also asked why the killer was granted bail after he chased and slashed a 16-year-old teenager at Portobello Beach four months earlier, saying he should have been detained in a secure unit.

"It's his first offence, and he's used a knife, so why was he just allowed to walk free?," she said.

The teenager admitted carrying out the attack at Portobello and murdering John McNab during an earlier court appearance.

For the defence, Mark Stewart KC said the teenage killer had acknowledged the harm and suffering his violence had caused to John McNab's family and friends.

Stewart said he was a young man with no previous convictions who had handed himself in after both attacks.

Since the murder, he has been diagnosed with autism and post traumatic stress disorder, the KC added.

He was detained without limit of time and will only be released if the parole board decides it is safe to do so.