A young man who stabbed his 15-year-old ex-girlfriend to death on the street was sentenced to life imprisonment with a minimum term of 17 years.

Logan MacPhail, then 16, stalked Holly Newton in Hexham, Northumberland, for an hour and then stabbed her 36 times in an alley.

CCTV showed him wearing a hat and baseball cap and disappearing as he followed Holly and her friends through the city centre.

He also stabbed a young boy who intervened to stop the attack.

He was found guilty of murder after a trial at Newcastle Crown Court and was sentenced at the same court on Friday.

Last month, a judge lifted a reporting restriction that prevented the media from identifying him because of his age.

The prosecution said MacPhail, who has autism and learning difficulties, did not accept that their 18-month relationship was over.

The night before he killed Holly, he drove 40 miles from his home in Gateshead to his home in Haltwhistle, Northumberland, where he hung out for hours.

MacPhail was eventually taken home by police, whose mother warned him that he was missing.

Holly’s mother, Micala Trussler, was concerned enough to contact the police and arranged to meet with an officer the next afternoon about MacPhail’s behavior.

That same afternoon, MacPhail stabbed Holly to death.

MacPhail, who met Holly when they were both cadets, claimed he never planned to attack Holly but wanted to use the knife to kill himself, but the jury rejected his story.

In a victim statement on Thursday, Ms Trussler said she could not be with her mortally wounded daughter in hospital because her body “was a crime scene”.

The mother-of-four said Holly and MacPhail had a typical teenage relationship at first, but her daughter noticed Holly was controlling her.

Ms Trussler believed that her daughter, although under 16 at the time, was a victim of domestic violence and that her ex-partner was causing emotional turmoil.

He changed his social media passwords and made them believe he could access their accounts and threatened to harm himself.

The night before the murder, MacPhail repeatedly tried to gain permission to enter Holly’s home and hung around for hours trying to persuade one of her siblings to open the door.

“I’m scared to think what might have happened to the rest of my family if he had been allowed in,” the mother said.

During the two-day sentencing hearing, there were discussions about MacPhail’s learning disabilities, autism and criminality.

Prosecutor David Brooke KC said the teenager was able to travel alone to Haltwhistle from his home in Gateshead the night before the murder, follow Holly into Hexham in disguise and lie to her about his whereabouts.

“He was perfectly capable of making rational choices,” Mr. Brooke said.

Nigel Edwards KC, defending, said MacPhail’s progress since entering secure accommodation had been “very rapid”.

Sentencing MacPhail, Mr Justice Hilliard said: “The fact is that you made a conscious decision to stab a 15-year-old girl to death in a public place with a knife you were unlawfully carrying, and stalked her around the town for a period of one hour, all of it.” Because your relationship with him has ended.

“You were jealous of the fact that he could see someone else.

“What happened in this incident should not happen to any child or parent,” he said.

The judge described the attack, which lasted more than a minute, as “evil and brutal”.

Speaking of the family’s loss, Mr Justice Hilliard added: “So many years ahead for a 15-year-old girl that she and they will never see.”

MacPhail admitted manslaughter but was found guilty of murder and willful wounding of the young boy.

The boy was stabbed four times by MacPhail after trying to stop the fatal attack and said he was now struggling with his mental health.

In his victim statement to the court, the young man, whose identity could not be identified by the media due to his age, said that he found GCSE exams difficult after the attack and had difficulty concentrating.

He said: “I wouldn’t wish this on anyone. I can’t imagine what Holly’s family is going through.

“Whatever punishment Logan receives will not change what happened that day.”