Caroline Kayll murder: Cage fighter Paul Robson found guilty

Paul Robson had denied murder, attempted murder and blackmail

A cage fighter has been convicted of murdering his teacher ex-partner after blackmailing her about an unlawful relationship she was having with a 15-year-old boy.

Paul Robson inflicted fatal head injuries on Caroline Kayll, 47, during a sustained attack on her and the boy at her Northumberland home in November.

The boy suffered multiple injuries.

Robson, 50, of Stanley Street, Wallsend, was also found guilty of attempting to murder the teenager.

Newcastle Crown Court heard the "cruel and calculating" cage fighting coach and former MMA fighter had 21 convictions for 92 offences over more than 30 years.

He claimed to have first met Mrs Kayll in 2005 while he was an inmate at a prison where she worked as an education officer.

At that point they began a clandestine affair which resumed years later when he was jailed again in 2014 for drug and firearms offences.

After Mrs Kayll left her prison officer husband, Robson moved into her home in Linton, near Ashington, on his release.

Caroline Kayll had worked as a social worker, a police officer, a prison-based teacher before moving into a school role

They split up weeks before the murder when he discovered she was in an illicit sexual relationship with the boy, who cannot be named for legal reasons.

Robson threatened to "ruin her" by exposing the relationship and in exchange for his silence, over 10 days in November, Ms Kayll paid him £29,000 and took out a £10,500 loan.

However, on 15 November, Robson drove three hours from Glasgow to Linton, having bought a locksmith's bar, a GPS car tracker, screwdrivers, pliers, a wrench and ammonia.

The ex-convict was later caught on CCTV "prowling" outside Ms Kyall's house.

The court heard that during the "vicious" assault Robson kicked his former partner in the head, possibly strangled her, slashed her with a blade, cut off clumps of her hair and cut up her clothes.

He also used a variety of knives to attack the boy, sprayed both his victims with ammonia and stole their phones so they could not call for help.

Robson then fled to Glasgow and remained at large while police made appeals to trace him. Ms Kayll was placed on life support at hospital in Newcastle but died days later.

He later blamed her murder on the boy, whom he claimed had attacked him and he injured in self-defence.

Ex-convict Paul Robson ran cage fighting fitness programmes

Following the conviction, Det Insp Graeme Barr of Northumbria Police described the case as "one of the most violent offences" he had ever investigated.

He said: "His attack on Caroline and his teenage victim was pre-meditated and demonstrated horrendous levels of violence.

"There is no doubt he wanted to kill or permanently disfigure both of his victims.

"He succeeded in killing his former partner and has left his teenage victim scarred for life.

"Not only that, but he spent the days that followed trying to avoid police before attempting to pin Caroline's murder on a vulnerable, teenage boy.

"There is a very real chance he will never experience freedom again and I hope that can bring some justice to his victims."

Robson will be sentenced on Wednesday.