In harrowing footage that left family members fleeing a Scottish courtroom in tears, 22-year-old John McNab can be heard desperately begging for his life in the final moments before a knife-wielding teenager chased him down and repeatedly plunged a hunting knife into his body on a busy Edinburgh street. The brutal, unprovoked killing has sparked fresh outrage over Scotland’s knife crime epidemic and the shocking decision to free a violent youth on bail just months before he struck again with lethal consequences.

The nightmare unfolded in the early hours of Tuesday, September 2, 2025, on Great Junction Street in Leith. John McNab, described by loved ones as the “life and soul of the family” — a vibrant young man full of dreams and laughter — was going about his night when a masked 16-year-old emerged from the shadows like a predator. The attacker had lain in wait in bushes, armed with what prosecutors called a “Rambo-style” hunting knife. What followed was captured in stark, enhanced CCTV that prosecutors played at the High Court in Edinburgh — footage so disturbing it forced some of John’s grieving friends and relatives to leave the room.

In the final seconds of his life, John’s terrified voice echoed across the street. “Please, please don’t. I haven’t done anything,” he pleaded as the youth closed in. Moments later, the blade struck again and again. John collapsed, bleeding heavily from multiple stab wounds, crying out in agony: “Help me, help me, I’m dying.” Emergency services rushed to the scene near Bonnington Road around 2:10 a.m., but despite their efforts, John was pronounced dead at the scene. A promising young life extinguished in a senseless frenzy of violence.

The killer — who cannot be named for legal reasons due to his age — was just 16 at the time. He has now admitted to John’s murder at the High Court this week, along with a separate serious knife attack on another teenager months earlier. That earlier assault took place on Portobello Promenade in March 2025. Despite being charged with attempted murder or serious assault involving a blade, the youth was released on bail — a decision that allowed him to roam the streets of Edinburgh and ultimately claim John McNab’s life just four months later.

This case has ignited fury across Scotland. How was a teenager already known to police for knife crime allowed back onto the streets? Critics are pointing fingers at a justice system they say is too soft on young offenders, especially those armed and dangerous. John’s devastated family, led by his heartbroken mother Lisa Petrie, has been left to pick up the pieces of a life violently stolen.

Lisa has spoken movingly of the unbearable pain that “will never be healed.” In powerful statements, she described her son as a kind, fun-loving young man whose smile could light up any room. Friends echoed those tributes, calling John “one in a million” and remembering the crowds that gathered at Leith Links for an emotional memorial shortly after his death. Many wore T-shirts bearing his image as they mourned a young man taken far too soon.

The chilling CCTV evidence presented in court painted a clear picture of a calculated and merciless attack. The teenager waited in ambush before launching his pursuit. John, realising the danger, tried to flee but was quickly overpowered. The footage, enhanced for clarity, captured not just the horrifying violence but John’s desperate human pleas for mercy — words that now haunt everyone who has heard them. Courtroom observers described the atmosphere as heavy with emotion as the reality of those final seconds played out on screen.

Prosecutors revealed John was stabbed multiple times in a frenzied assault. He was found seriously injured on the pavement and despite the rapid response of paramedics, nothing could save him. The attacker fled but was quickly identified and arrested. He later pleaded guilty to murder and the earlier blade attack, meaning he now faces a life sentence when sentenced at a later date.

John’s mother has channelled her grief into action. Lisa Petrie has become a passionate campaigner for tighter restrictions on knife sales and better support for victims of knife crime. She has met with Scottish government ministers, pushing for “bleed kits” to be distributed more widely across Edinburgh and for stronger laws to keep dangerous weapons out of young hands. Her campaign gained momentum after her son’s death, highlighting how easily lethal blades remain available despite repeated promises of crackdowns.

The killing has thrown a harsh spotlight on Edinburgh’s — and Scotland’s — ongoing battle with knife crime among young people. Leith, a vibrant but sometimes troubled part of the capital, has seen its share of violence, but the random and brutal nature of this attack has shaken the community. Locals spoke of their horror at a young man being hunted down on a public street in what should have been a relatively safe area.

Friends remember John as someone full of potential, with a bright personality and strong family ties. He was the kind of son any parent would be proud of — caring, sociable, and always ready with a joke. His death has left a massive void. One tribute summed up the collective pain: a young life full of promise, ended in seconds by a blade in the hands of someone who should never have been free to carry it.

The teenager’s previous offence involved slashing another 16-year-old boy, leaving him with serious injuries. That he was bailed despite the severity of that incident has raised serious questions about risk assessment in Scotland’s courts. Police and prosecutors have faced scrutiny over whether enough was done to monitor him or restrict his movements after the first attack.

As the legal process moves forward, John’s family continues to grieve while demanding change. Lisa Petrie’s determination to prevent other families from suffering the same nightmare has become a beacon of hope amid the tragedy. She has spoken of the “horrible way” her son’s life was taken and vowed to keep fighting so that no other mother has to bury her child because of knife crime.

The broader implications stretch far beyond one family. This case adds to a grim tally of knife-related deaths in Scotland, reigniting debates about youth justice, stop-and-search powers, and the culture that allows young people to carry blades as status symbols or tools of intimidation. Campaigners argue that soft policies on repeat offenders are costing lives — and John McNab’s death is the latest tragic proof.

In the streets of Leith, floral tributes and messages still mark the spot where John fell. “Gone but never forgotten,” “Rest in peace, John,” and heartfelt notes from friends reflect a community united in sorrow. The Great Junction Street area, usually bustling with everyday life, now carries the weight of a violent memory that refuses to fade.

For those who loved John, the pain is daily and relentless. The sound of his voice on that CCTV — begging a stranger for mercy he would never receive — is something no parent or friend should ever have to endure. Yet that footage, as painful as it is, may serve as a powerful catalyst for change, forcing authorities to confront the failures that allowed this tragedy to happen.

John McNab was not a gangster or a troublemaker. He was an ordinary young man whose path crossed with extraordinary evil on an ordinary Edinburgh street. His final words — “Please, please don’t. I haven’t done anything” — stand as a heartbreaking plea not just for his own life, but for every family praying their child comes home safe at night.

As the 17-year-old killer awaits sentencing, Edinburgh and the rest of Scotland are left asking the same anguished questions: How many more young lives must be lost before knife crime is treated with the urgency it deserves? How many more mothers must campaign for justice after their sons are stolen in the night?

John’s story is a raw, unflinching reminder of the human cost behind the statistics. A 22-year-old man with everything to live for, reduced to begging on cold pavement as blood poured from his wounds. His death was not inevitable — it was preventable. And that truth makes the grief even sharper.

In the end, John McNab’s final moments captured on CCTV will forever echo as a cry for help that came too late — and a call to action that Scotland can no longer ignore.