A domestic abuser sentenced to a whole life order for the murders of his ex-partner and her new boyfriend has lost a bid to have his jail term reduced at the Court of Appeal.

Marcus Osborne was jailed in March for the knife attack which left Katie Higton, 27, with 99 injuries; and Steven Harnett, 25, with 24 wounds including mutilated genitals; after which he compared them to Romeo and Juliet and said they could “die together now”.

Leeds Crown Court heard that Osborne, who was 35 when he was sentenced, lay in wait for Ms Higton and attacked her as she entered the house they once shared in Huddersfield, West Yorkshire, in the early hours of May 15 last year.

He then used Ms Higton’s phone to pretend to be her to lure Mr Harnett to the house before killing him while four children were inside the property, going on to rape another woman at knifepoint.

Earlier on Wednesday, Osborne’s lawyers told the Court of Appeal that the sentence should be reduced as the judge had failed to take into account his guilty pleas, and that the whole life order was “not necessary”.

But three senior judges dismissed the appeal bid, with the Lady Chief Justice Baroness Carr describing the killings as “planned and brutal murders motivated by sexual jealousy”.

She said: “(The sentencing judge) was entitled to consider this was not a borderline case, and to be in no doubt as to its gravity, being of such exceptional seriousness that even a very long minimum term would not amount to just punishment.

“The facts of these two murders, together with their associated offences and taking into account relevant aggravating factors, are so horrific, that whole life terms were appropriate, despite the applicant’s guilty pleas.

“At the end of the day, these were two planned and brutal murders motivated by sexual jealousy and involving sexual conduct, committed in circumstances designed to maximise the depravity of the murders by an individual with a history of significant violence against one of the victims, and previous domestic partners.”

Marcus Osborne court case
Katie Higton was killed by her former partner (West Yorkshire Police/PA)

Osborne’s sentencing hearing was told that Ms Higton had been in a relationship with him for five years, but left him in early May last year after an assault which was “the last straw”.

Ms Higton had complained to police that the relationship was “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.

In the days before the murders, she also told West Yorkshire Police that 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 May 12 last year and bailed with conditions not to go back to their home, but spied on Ms Higton over the following days and found out about the developing relationship between her and Mr Harnett by hacking into her Snapchat account.

He later admitted two counts of murder and single counts of rape and false imprisonment, and already had convictions for violent offences against two previous partners.

The sentencing judge, Mrs Justice Lambert, said that Osborne was heard saying: “I warned you I was going to kill you … this is your fault this is happening” as he attacked Ms Higton, and was described as washing himself between killings, laughing and jeering.

He later invited a neighbour into the living room to see the bodies, which the judge said was “as if you were proud of what you had done”.

Steven Harnett (West Yorkshire Police/PA)
Steven Harnett (West Yorkshire Police/PA)

She said that the crimes were “horrific” and that “even a very long minimum term would not amount to just punishment”.

John Elvidge KC, for Osborne, told the court in London that his guilty pleas should have been given “heavy weight” as they spared the rape victim from having to give evidence.

But Baroness Carr, sitting with Lord Justice Jeremy Baker and Mr Justice Bennathan, dismissed the challenge, stating that some of Ms Higton’s injuries “were inflicted with the intention of disfiguring as well as killing” and that the original sentencing decision “cannot be impugned”.

She said: “We do not accept the submission that the judge inappropriately reduced the weight to be attached to the applicant’s guilty pleas.”

Osborne attended the hearing via a video link from HMP Wakefield, wearing a grey Adidas jumper, and did not react as his appeal bid was dismissed.