A man who used a kitchen knife to murder his “prodigiously gifted” former girlfriend at the flat they shared has been jailed for at least 15 years.

Joe Atkinson, 25, was “fuelled by jealousy” when he inflicted a “long and brutal death” on 24-year-old Poppy Devey Waterhouse who, like him, had a masters degree in maths.

Leeds Crown Court heard he had failed to come to terms with Miss Devey Waterhouse breaking off their three-year relationship in October, having become a couple while they were studying in Nottingham.

Prosecutors said she had been due to move out of the flat in Richmond Hill, Leeds, days after Atkinson came in during the early hours of December 14 and used the blade to inflict more than 100 injuries on her.

Joe Atkinson
Joe Atkinson (West Yorkshire Police/PA)

The court heard that the attack started in the bedroom of the victim, a data analyst at William Hill, before moving into the hallway, where she is believed to have frantically attempted to escape through the front door.

Atkinson is said to have later rearranged the scene, placing a different knife next to her body, before calling his father, telling him: “We had had an argument and things would have been all right if she hadn’t attacked me.”

He maintained that story for months, initially pleading not guilty to murder before changing his plea on April 5.

On Friday, friends and family of the victim and her killer listened as he was handed a life sentence with a minimum of 15 years and 310 days.

Taking into account time he has already spent in custody, Atkinson will have served a minimum of 16 years and two months before he can be considered for release.

The Honourable Mr Justice Lavender told Atkinson: “Poppy Devey Waterhouse was a young woman with so much going for her.

“She had earned a first class honours degree and was excelling in her chosen career. She had so many opportunities in her life, but you brought an end to that.

“You put an end to it, and brought misery to the lives of her loved ones.”

The court heard that, a month before the “savage and brutal” attack, Atkinson had punched Miss Devey Waterhouse’s new boyfriend.

On the morning of the killing, ambulance staff found the “much loved” victim, originally from Frome in Somerset, in a pool of her own blood, prosecutors said.

Jason Pitter, prosecuting, said: “Poppy Devey Waterhouse was a prodigiously talented mathematician, who was described as brilliant and beautiful, who, at the age of 24, had her whole life ahead of her.

“It was a life cruelly taken away from her just before Christmas last year because this defendant realised he was not going to be a part of this future.”

During a police interview after the killing, Atkinson is said to have told officers: “I don’t know how many times I stabbed her, I just didn’t stop until it went calm and she stopped moving.”

In a powerful victim impact statement read out in court, Miss Devey Waterhouse’s mother, Julie Devey, said: “As a parent, my basic duty is to make sure that I keep my children safe. I failed, and I have to carry that failure with me at all times, wherever I go, whoever I am with, whatever I am doing.

“I kept stroking my hands across the floorboards where she had been left screaming and dying. I just wanted to scoop her up and save her.

“I now live my life with a split screen. On one half I can see the now, and on the other half that horrific scene.”

After the sentencing, Claire Harris, from the Crown Prosecution Service, said: “Poppy was bright and beautiful, with her whole future ahead of her.

“Atkinson cruelly and horrifically extinguished this promise.”

Detective Superintendent Nicola Bryar, of West Yorkshire Police, explained how Atkinson’s attempts to claim that the killing had been a self-defence unravelled.

She said: “He gave a false account in our interviews with him after his arrest, but through detailed and comprehensive inquiries we were able to build up a true picture of what had occurred.

“We also established that he had spent some significant time disposing of evidence and attempting to alter the crime scene over the hours before the ambulance service and police were called to the flat.

“He has never explained why he did what he did, but he will now have a significant period of time in prison to reflect on what he has done and the hurt that has caused to so many people who knew and loved Poppy.”