The GUARDIAN: LONDON, England, By Jessica Murray – Surrounded by quiet residential streets and the grounds of a primary school, Stowlawn playing fields in Wolverhampton are normally a place where teenagers kick a football around and children pass through as they walk home from school.

When Shawn Seesahai came across two 12-year-old boys hanging out in the park with a friend, he would not have expected one of them to be carrying a deadly weapon, or that minutes later they would use that weapon to kill him in a brutal, random attack.

Exactly what happened between Seesahai first coming into contact with the boys and them stabbing him with a machete was highly contested during the trial. The prosecution said Seesahai, 19, “had offered no violence, nor done anything to offend” the two boys before he was killed. He was a stranger to them, stumbled across them by chance and became a victim of their obsession with the weapon with which they had been posing for photos hours earlier.

A friend who was with Seesahai said they had been sat on a bench discussing their plans for Christmas before the boys attacked – Stephanie Wareham/PA Media

Derron Harrigan, Seesahai’s friend, who was with him on the evening of the murder, said they were threatened by the boys while they were sat on a bench discussing their plans for Christmas.

He said one of the boys “shoulder-barged” Seesahai, before reaching for the blade and shouting “run bro”. “The dude took it out of its sheath,” he told the court. “We started to run but Shawn tripped. I was running for my life – I couldn’t stay there and watch.”

Giving evidence in court, the two boys claimed Seesahai had asked them to move off the bench. One said he had been put in a headlock by Seesahai, and his friend had used the weapon to threaten him.

Rachel Brand KC, representing the youth who admitted owning the machete, suggested the incident had been “sparked” after the defendants were aggressively asked to move. She said it may have been a “sudden and unexpected fatal stabbing” by a boy who “panicked or lost his head”.

Regardless of the exact sequence of events that triggered the stabbing, the fact that two boys so young were responsible for the violence has shocked those involved in the case. “In my career, I have not come across children as young as 12 carrying and using a machete in the manner which has been described in court,” said DI Damian Forrest from West Midlands police, the senior investigating officer in the case.

“I have been a police officer for 20 years and this isn’t the first time I’ve been out to a young man who has lost his life in a really violent way, but to then find out that two 12-year-olds were responsible was shocking and made us all on the investigation team stop and pause and think about things.”

Throughout the trial, both boys wore a shirt and tie as they sat flanked by intermediaries who helped explain court proceedings to them – while they used fidget aids to help calm their nerves.

It was a sharp reminder of how young they are, and how dangerous weapons are falling into increasingly younger hands. The youth who owned the 42.5cm-long black-bladed machete refused to name the person he bought it from for £40. He was reported to be obsessed with knives and nonchalant about the stabbing, telling friends in one message: “It is what it is.”

He carried it around concealed in his trouser leg and sent photos of him masked and holding it to friends because he “thought it was cool”, he told the court.

Neither boy had any previous convictions, cautions or reprimands. After a random encounter in a Wolverhampton park, they have now become the UK’s youngest convicted murderers since Jon Venables and Robert Thompson were found guilty of James Bulger’s murder in 1993.