Couple killed in brutal attack by jealous ex Marcus Osborne

Marcus Osborne is being sentenced in a two-day hearing at Leeds Crown Court

A mother and her new love interest were brutally murdered by her former partner out of "sexual jealousy", a court has heard.

Marcus Osborne, 35, stabbed Katie Higton and Steve Harnett in an attack at a house in Huddersfield on 15 May 2023, before raping another woman in the property.

He had previously admitted two counts of murder, false imprisonment and rape.

Osborne is being sentenced in a two-day hearing due to conclude on Friday.

Prosecutors at Leeds Crown Court said Osborne had forced his way into the house, at Harpe Inge in Dalton, which he once shared with Katie Higton, armed with a knife.

The 35-year-old then waited for Ms Higton's return, from a cinema date with Mr Harnett, and brutally attacked her as soon as she came through the door.

Leeds Crown Court was told Ms Higton, 27, sustained 99 injuries in the assault.

Prosecutor Jonathan Sandiford KC said she "was effectively defenceless, although she put up a courageous struggle".

Osborne then used Ms Higton's phone to pretend to be her and lured Mr Harnett, 25, to the property.

Katie Higton sustained 99 injuries in the fatal assault

He then murdered Mr Harnett, who was left with 24 knife wounds, which included an injury inflicted when he was thought to be still alive, which showed "sadistic conduct".

Another woman who was in the house told police that Osborne moved the bodies so they were side by side before remaining in the house for several hours.

He then raped the other woman, whom he had held captive in the house overnight, at knifepoint.

Children were also in the house during the murders, the court heard.

Mr Sandiford said: "The defendant committed a premeditated and brutal double murder motivated by sexual jealousy, a desire to exercise control over Katie Higton, an unwillingness to accept her decision to leave him and her freedom to form a relationship with another man."

Ms Higton had been in a relationship with Osborne for five years, but left him in early May last year after an assault on 28 April which was "the last straw".

Steven Harnett was lured to Ms Higton's house by Osborne, who had used her phone

She later told police the relationship had become "coercive, controlling and physically abusive" in the last two years and that she had been regularly assaulted, including one incident when he threw a cat at her, the court heard.

Osborne also had convictions for violent offences against two previous partners in 2011 and 2012, Mr Sandiford said.

Ms Higton went to Huddersfield police station on 10 May to make a complaint about Osborne, and spoke to a member of police staff over the phone later that day and was visited by an officer on 11 May.

During phone calls to the police Ms Higton said Osborne had told her "he would slit her throat if she said what he had done" and that "if she ever got a boyfriend he would kill them both".

Osborne was arrested on suspicion of domestic violence offences on 12 May and bailed with conditions not to go back to their home, but spied on her over the following days before taking a taxi to the house on the night of the murders.

The court heard he had found out about the developing relationship between Ms Higton and Mr Harnett by hacking into her Snapchat account.

West Yorkshire Police launched a murder investigation after being called to Ms Higton's Huddersfield address

A victim personal statement by Ms Higton's mother Nicola McAlister, read in court, described Osborne as "a monster of the worst kind".

"I no longer live, I simply exist in a tortuous world without my baby," Ms McAlister wrote.

"I am tormented every second of every day that I draw breath."

Osborne did not react to the details of the offences during the first day of his sentencing hearing on Thursday.

He repeatedly looked towards the public gallery, where members of Mr Harnett's family could be heard sobbing.

Mr Sandiford said the prosecution would argue that Osborne's crimes are serious enough that a whole-life order should be imposed.

The hearing continues.