A 15-year-old girl had a “typical teenage relationship” with a boy before he murdered her, her mother has told a court.

Holly Newton was repeatedly stabbed in an alley in Hexham, Northumberland, in January 2023 by Logan MacPhail, then aged 16.

MacPhail, now 17, from Birtley, Gateshead, was found guilty of Holly’s murder and wounding another boy who had tried to stop the attack.

A two-day sentencing is under way at Newcastle Crown Court, with prosecutors saying it was a “brutal” and planned attack carried out by the “jealous” teenager.

MacPhail secretly followed Holly for about an hour after she left school on the afternoon of 27 January, before attacking her in an alley next to a pizza shop.

The teenager claimed he had gone “blank” at the time and only meant to harm himself, but jurors rejected that.

During cross-examination at his trial, he admitted he had been angry with Holly and intended to stab her but then retracted that confession.

Holly’s mother Micala Trussler told the court MacPhail had been Holly’s “first and only” boyfriend and it was a “typical teenage relationship” with “ups and downs”.

She said MacPhail would spend weekends with Holly’s family and their relationship had shown “no red flags” until towards the end when Holly wanted to break it off.

Ms Trussler said it was clear her “caring and thoughtful” daughter had been more mature than MacPhail but when she had tried to break up with him, he had used “emotional blackmail” and scared Holly.

“I was not aware of the sheer scale of turmoil Holly was going through at the time,” she said, adding MacPhail had been “obsessed” with Holly and “thought if he couldn’t have [her], no-one else could”.

Holly was a quiet girl who loved dancing and had a “strong sense of right and wrong”, her mother said.

She said MacPhail “knew exactly what he was doing” when he went to Hexham that day and seeing the CCTV footage of him following Holly “chills me to my core”.

Ms Trussler said during the trial MacPhail had attempted to portray her “caring, kind daughter” as a “nasty, unfaithful girlfriend” but that “could not be further from the truth”.

She said Holly’s death felt like a part of her heart had been ripped away, with the pain “indescribable”.

Prosecutor David Brooke KC said a life sentence with detention was mandatory for murder but the debate was about the minimum term MacPhail should serve before being eligible for release.

The issues revolved around the degree of planning and premeditation, amount of mental and physical suffering inflicted on Holly and MacPhail’s motivation for having a knife, the court heard.

“This was a brutal attack,” Mr Brooke said, adding it had lasted more than a minute and there had been more than 20 blows causing 36 knife wounds, which “spoke to the intensity of intention”.

He said it would be a 10-year starting point if MacPhail’s claim, that he had only taken the knife to harm himself, was accepted, but 17 years – 25 years for an adult – if it was determined he took the weapon with the intention of using it to cause “at least really serious harm”.

The prosecutor said MacPhail had been intent on seeing Holly and messages he had sent demonstrated his “jealousy” and “unhappiness with how he felt he had been treated”.

Mr Brooke said MacPhail had followed her in disguise for an hour and waited until she was alone, before he approached and then “enticed” her into the alley, where the prosecutor said he intended to attack her.

There was dispute about MacPhail’s childhood trauma and how much of an impact that may have had on his actions, the court heard.

Mr Justice Hilliard said the teenager had been seen by “an awful lot” of medical experts, including multiple psychiatrists, but there had been no “secure diagnosis” of post-traumatic stress disorder made.

He said MacPhail had undoubtedly witnessed and experienced domestic violence, seeing “severely distressing” things “that plainly no child should have to”, but quite how significant it was in what he had done was “not really clear”.

The court heard MacPhail had been diagnosed with autism spectrum disorder and a low IQ but Mr Brooke said the youth’s functioning was “quite a bit higher” than had been suggested by MacPhail’s legal team.

Mr Brooke said MacPhail’s planning was “disturbing” and the teenager had been “perfectly able to make rational decisions and understand the consequences” of his actions.

The prosecutor noted MacPhail had a history of harming himself with a knife, so clearly knew what the weapon could do.

Mr Justice Hilliard said he felt it had been proved that “over time doctors under-estimated [MacPhail’s] abilities” but he would consider the teenager’s maturity.

In mitigation, Nigel Edwards KC said MacPhail’s premeditation was “limited” and there was a “spontaneous eruption” of violence in a “fast-moving” situation.

He said MacPhail became “angry and lashed out” but he had been speaking to Holly for about 15 minutes before he actually attacked her.

Mr Edwards also said MacPhail only intended to cause “bodily harm” rather than kill Holly.

He said the teenager had had an “unconscionable” childhood with years of abuse, which was a “significant” mitigating factor, but it did not excuse his actions.

Mr Edwards said MacPhail described himself as a “monster” who “no-one could love”.

The hearing continues.

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