Teen admits to murder of John McNab as heartbroken mum Lisa Petrie says she'll 'continue fight in his honour'

The young man, who cannot be named for legal reasons, admitted to stabbing and killing Mr McNab in the Leith area in September 2025. He also pleaded guilty to a separate serious assault charge which took place in March 2025.

Mr McNab was found injured at the corner of Bonnington Road and Great Junction Street at around 2.10am on Tuesday, September 2.

The 22-year-old died at the scene.

In a statement, John’s mother Lisa Petrie said: “Today, the accused pleaded guilty to the murder of my beautiful son John. While this plea brings some sense of closure, it cannot undo the devastation we feel as a family.

“My son’s life was taken far too soon in a horrible way, and the pain of his absence will never be healed. No sentence, no ruling will bring him back.

I have lost my best friend, my beautiful baby boy. However, in his memory, I am still committed to making a difference.”

Lisa launched the ‘Not In Vain’ campaign following John’s death in September 2025, including advocating for easily accessible bleed kits and banning the sale of knives in supermarkets.

She added: “I am still actively campaigning against the sale of knives in supermarkets. No one should be able to easily purchase the tools that can destroy lives and families.

“The tragic loss of my son by such an easily accessible weapon is a constant reminder of the dangers that come from this unchecked availability.

“I will continue to fight for change, not just for my John but for the sake of every family.

“Additionally, my campaign making bleed kits more widely available is essential. These kits could save lives. If they had been available sooner John might still be here with us today.

“We must ensure that every person, no matter where they are, has access to the tools they need in a life-threatening situation. It’s a small step that could mean the difference between life and death.

“I will continue this fight in honor of John. His death will not be in vain. I will keep pushing for these changes until we see a world where no parent has to go through what I am living.”

In the separate incident in March 2025, a 17-year-old male youth was rushed to hospital after being found on The Promenade in Portobello with stab wounds at around 8.45pm on March 21.

Detective Inspector Kevin Tait, senior investigating officer, said: “Our thoughts are with the family and friends of John McNab at what is a very difficult time for them. And also with the victim seriously injured in the separate incident.

“An extreme level of violence was used in these incidents. This kind of behaviour is never acceptable and will not be tolerated. This conviction sends a message to anyone carrying knives that they will be apprehended and dealt with robustly.

“I would like to personally thank the officers who worked on these harrowing investigations and the public who significantly assisted my investigation team.”

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Superintendent Neil Wilson added: “I can’t stress enough the devastating impact weapon carrying and use has on our communities and our thoughts go out to all who have been affected by this type of crime.

“Officers regularly carry out patrols in areas where knife crime is reported and we urge the public to support us and get in touch with any information or concerns that they have.

“While bringing offenders to justice is vital in keeping communities safe, education to prevent offending happening in the first place is key, along with promoting positive life choices.

“We have a number of new initiatives on violence prevention in Edinburgh involving partners and young people and details will be unveiled in the coming months. These will focus on raising awareness of the dangers of carrying weapons and the impact of violence.

“Edinburgh is a safe place to live, work and visit but we will not be complacent. We know that violence remains a concern in our communities and we’re determined to do everything we can to reduce harm and keep people safe.”

The 17-year-old male youth will be sentenced at a later date.