A Sixth Form student was fatally stabbed through his heart after leaving his school prom, a jury heard today (Tuesday).

Kajetan Migdal, a pupil at John Henry Newman School in Stevenage, and three friends were changing clothes, intending to go onto a club, when they were confronted by a stranger in a balaclava who said: "You from these ends?"

Patrick Sharp-Meade, now 20, wrongly believed the group had spoken to his ex-girlfriend, pulled a knife from his trousers and stabbed 18-year-old Kajetan in the chest.

The Year 13 student was rushed to hospital, where he died in the early hours of the next morning, Luton Crown Court heard.

Patrick Sharp-Meade, of Cuttys Lane in Stevenage, denies murder.

At the start of the trial, Judge John Hillen told the jury: "He accepts he stabbed and killed Kajetan.

"The issue is whether he is guilty of murder or manslaughter on the grounds of diminished responsibility."

Kajetan was stabbed in Cuttys Lane in Stevenage at 11.20pm on May 27, 2022 and died at 4.05am the following day.

Opening the case, prosecutor Jane Bickerstaff KC said: "The defendant has pleaded guilty to possessing a bladed article - the weapon he used.

"He has also pleaded guilty to possessing a small number of wraps of cocaine that were found in his shoe when he was arrested."

She said Sharp-Meade lived in a flat in Cuttys Lane, near where Kajetan had parked his car.

Ms Bickerstaff said: "It was a wholly unprovoked attack in a residential street in Stevenage. This defendant and Kajetan Migdal were both 18 and complete strangers.

"What was supposed to have happened is that Kajetan should have enjoyed a school prom at the Holiday Inn hotel in Stevenage. Then he should have headed on with his friends - three of them - to Cambridge to join his classmates at a club bar for an after-party. None of that should have brought him in contact with the defendant."

She said Kajetan had parked in Cuttys Lane close to the Holiday Inn. After the prom, the four friends returned to the car to change from their prom suits into clothes more suitable for the bar in Cambridge. They intended to travel there by train.

The prosecutor went on: "They never made it to Cambridge. They were approached by the defendant, who was armed with a large zombie-style knife. He had it concealed down his tracksuit trousers.

"He verbally challenged Kajetan and his friends in the pretence that they had been following or speaking to his ex-girlfriend as she walked past the group.

"It caused Kajetan’s friends to back away. He had not quite finished changing and momentarily stood his ground. The defendant approached, pulled out a knife and stabbed him straight in the chest. It pierced his heart. Kajetan staggered into the road and the defendant fled the scene.

“Kajetan was treated in the road and quickly transferred to the Lister Hospital, but the injury was catastrophic. He died at five past four in the morning."

The jury was told the defendant’s ex-girlfriend was heading to Sharp-Meade’s flat to collect a fur hood. As she walked past the group, she was talking to a friend on her mobile.

The defendant, who was in the flat with the person taking the call, heard the conversation and could hear the four teenagers talking in the background.

The prosecutor said: "As a result of hearing them in the background, he became irrationally jealous.

"The defendant armed himself with a knife. Once the ex-girlfriend arrived, he threw her hood at her. He put on a balaclava and sped-walked to find and confront those who he wrongly thought had engaged with her."

She said the defendant had been "enraged by something that had not happened."

After the stabbing, Sharp-Mead returned to his flat and hid the knife in his mattress. He left the scene, and at 2am was spotted by police and arrested.

Case proceeding.