A young woman said she is trapped in the nightmare moment her obsessed ex-boyfriend stabbed her new partner to death.

Alicia Parrin, girlfriend of Harrison Tomkins, from Haywards Heath, counted the blows as she delivered her powerful victim statement to a packed courtroom.

"One, two, three, four, five, six, seven, eight, nine, ten. That's how many times he put the knife in Harrison," she said.

Kaydon Prior, 23, and his accomplice Jason Curtis, 22, were jailed for life after a jury found them both guilty of murdering Mr Tomkins, a 25-year-old lifeguard.

The Argus: Harrison Tomkins, 25, was murdered last AugustHarrison Tomkins, 25, was murdered last August (Image: Sussex Police)

Prior brutally stabbed Mr Tomkins, who died from his injuries at a flat in Arthur Road, Crawley, last August 13.

The 23-year-old will spend at least 28 years in prison before he can apply for parole.

Curtis, who did not stab Mr Tomkins, will spend a minimum of 22 years in prison.

Both wore black coats and ties at the Crown Court in Brighton where his honour Judge Jeremy Gold KC said they had executed a carefully planned killing of a man neither of them knew or had any reason to harm.

He told Prior: "This brutal murder was borne out of your obsession with Miss Parrin.

"She was exhausted by your coercive and controlling behaviour and made it clear to you she would no longer put up with it.

"You would not and could not accept that simple fact."

The judge said Prior had gone back to his own flat leaving Curtis to keep watch at Miss Parrin's.

"You went back to get the keys to her flat and to collect your knife, the murder weapon," the judge said.

Neither showed any emotion as the verdicts were handed down.

Both glanced back at their families in the public gallery as they were taken down.

At a trial in Chichester which ended on February 9, the jury was told the pair burst into Miss Parrin's bedroom where Prior ripped off the duvet and pinned Mr Tomkins to the bed at the knees armed with a 16cm long hunting knife.

The Argus: Harrison Tomkins' family outside Chichester Crown Court on February 9Harrison Tomkins' family outside Chichester Crown Court on February 9 (Image: Sussex News and Pictures)

Miss Parrin told a hushed court in Brighton: "I was 19 when I first met him and I will always regret the day.

"I don't think I'll ever truly be able to recover from the trauma of what he did to me and what he did to Harrison.

"I don't think I'll ever be able to un-see what I saw that night. The amount of blood that was on the bed.

"It was like the sheets had been dyed red," she said.

Miss Parrin, now 21, said she felt completely helpless as her ex attacked her new lover.

She fought back tears as she recalled the attack.

"Everything was in slow motion. I felt weak. I couldn't do anything to help Harrison."

She described Mr Tomkins as the complete opposite of jealous, controlling Prior.

"I will never be able to leave behind the fear he instilled in me,” Miss Parrin told the court of Prior.

"He didn't allow me to think for myself.

"I've lost my confidence in my own ability to make decisions."

As he left the flat, Prior grabbed Miss Parrin by the hair and punched her saying: "I should stab you too." 

Miss Parrin said she had lost her innocence and her teens.

The sound of keys in a door triggers memories of the attack, she said.

"I'm trapped in the nightmare of that night again.

"Before all of this, I used sleep to stop him hurting me.

"I can't do that any more.

"Whenever I close my eyes I see him coming into my room and doing those horrible things again," she said.

Mr Tomkins and Miss Parrin had spent their first night together and were sleeping when Prior and Curtis burst into the Crawley flat on August 13, last year.

Prior, described as jealous and controlling, ripped the duvet off before pinning Mr Tomkins to the bed and stabbing him to death with a hunting knife.

A witness described Prior screaming: “I love you,” at Miss Parrin as he repeatedly stabbed her boyfriend.

The trial has heard Prior refused to accept his relationship with Miss Parrin had ended. 

Following a night out in London with his best friend and accomplice Curtis, they went to Miss Parrin’s flat in Crawley. 

Curtis stayed behind while Prior returned to his own flat where he had a set of keys to Miss Parrin’s home. 

He returned with the keys and the knife.

Miss Parrin described Prior as controlling and violent during their year-long relationship.

She told police the obsessive neat freak was a drug dealer.

A search of his flat recovered £8,175 in cash. 

Prior tried to dismiss her screams coming from her flat as the “sounds of good sex” when he was confronted by neighbours. 

Prior phoned Miss Parrin twice after leaving her flat in bloodstained clothes as she was desperately calling 999. 

When emergency services arrived, Miss Parrin was covered in blood. 

The jury was shown harrowing images of her blood-soaked bed and police body-worn video of her moments after the attack. 

Amateur boxer Mr Tomkins was described as tall, muscular and well-loved.

He worked with Miss Parrin at the K2 leisure centre in Crawley and the pair first got together after he won a charity boxing match.

The jury found both men guilty of murder and having an offensive weapon.

Prior was also found guilty of assaulting Miss Parrin. 

The court heard Prior had previous convictions for burglary and possession of drugs.