A jilted 16-year-old boy who was obsessed with his former girlfriend fatally stabbed her new boyfriend after lying in wait for him with a knife after school, a court has heard.

The boy had changed out of his school uniform into a tracksuit and armed himself with a kitchen knife before confronting the victim in a “jealous rage” and goading him into a fight, Ipswich Crown Court was told.

Riel Karmy-Jones KC, prosecuting, said the 16-year-old boy, and Harley Barfield, who she described as being in a “love triangle”, had thrown punches at each other before the 16-year-old took a knife out of his pocket and stabbed Harley several times.

East Anglian Daily Times: Harley Barfield, 16, died two days after an incident in Haverhill in January this year. Harley Barfield, 16, died two days after an incident in Haverhill in January this year. (Image: Suffolk police)

Miss Karmy-Jones, described the attack as “frenzied” and said that Harley, also aged 16, received cuts to his neck head, cheek, and lip as well as three stab wounds to the left side of his chest one of which penetrated his chest.

She said that witnesses allegedly saw the 16-year-old boy chase after Harley with a knife and heard Harley screaming “stop”.

They saw the 16-year-old, who can’t be named because of his age, make two stabbing motions towards Harley who fell to the ground near a car park in Strasbourg Square, Haverhill.

They then allegedly saw the 16-year-old stab Harley while he was lying curled up in a ball on the ground.

The 16-year-old’s former girlfriend arrived on the scene and was screaming hysterically while one of her friends tried to stem the bleeding from Harley’s wounds.

A member of the public had performed CPR on Harley who appeared to have stopped breathing, said Miss Karmy-Jones.

After the incident, the 16-year-old had run from the scene and disposed of the knife.

He went to his grandparents and told them to call the police as he had stabbed someone.

An air ambulance was called to the scene of the stabbing and Harley was airlifted to hospital where, despite the efforts of doctors, he died on January 11.

East Anglian Daily Times: Floral tributes left in memory of Harley Barfield in Haverhill.Floral tributes left in memory of Harley Barfield in Haverhill. (Image: Charlotte Bond)

Miss Karmy-Jones said the fatal stab wound had penetrated his chest between his ribs and had entered the front of his heart and exited through the back.

A post-mortem examination showed he had died from multi-organ shock caused by a lack of blood circulation.

The court heard that following his arrest the 16-year-old boy initially claimed that Harley had been armed with a knife which he had picked up when it fell out of Harley’s pocket.

He claimed Harley had previously threatened to kill him and he had stabbed him in self-defence although he later accepted this wasn’t what happened.

Miss Karmy-Jones said that following the stabbing it was discovered that the 16-year-old had carried out Google searches on “how to stab someone without getting stabbed back” and “how long do you get for murder?”

“His phone shows he’d been thinking about murder for some time,” said Miss Karmy-Jones.

“The prosecution case is that he was so obsessed with his ex-girlfriend and jealous of her relationship with Harley that he murdered for her.”

“He was incredibly obsessed and incredibly jealous and saw Harley as standing in the way of him reuniting with his girlfriend,” she added. 

She said that on January 9 he’d been in a “jealous rage and had set out to get rid of Harley”.

The 16-year-old has denied murdering Harley Barfield on January 9 this year but has admitted manslaughter and possessing the knife that was used to kill Harley.

Miss Karmy-Jones told the court that by his pleas the defendant, who has been diagnosed with autism spectrum disorder ( ASD), accepted he was responsible for not only taking the knife to the scene and stabbing Harley but also that when he stabbed him he meant to cause him really serious harm and was responsible for his death.

Miss Karmy-Jones said the 16-year-old’s defence was that his ASD diminished his responsibility for the killing.

The trial continues.