A teenage boy who murdered his schoolgirl ex-girlfriend Ellie Gould has been jailed for life.
Thomas Griffiths, now 18, hung his head as the judge sentenced him to a minimum of 12 years and six months in prison.
Griffiths strangled then stabbed his ex-girlfriend to death at her family home in Wiltshire, after she ended their four-month relationship.
He previously pleaded guilty to the charges against him.
Friends and family of Ellie's packed the Bristol Crown Court as he was sentenced today.
The court heard how Ellie and Griffiths - a prefect - had been in sixth-form together and had known each other for some time.
They had been in a relationship since about January 2019 but the day before her death Ellie told friends she had split from the defendant having felt "suffocated" by him. She said he had not taken the break up well.
The next day Griffiths retaliated, driving to her home where they argued and he ultimately choked Ellie then stabbed her 13 times in the neck.
“What matters is that she had called a halt to the relationship as she was perfectly entitled to do. You say you were upset by that," said Mr Justice Graham.
“In my view, you were a great deal more than upset," he added.
“You and you alone know exactly what happened that day but what is clear is that at some point, you put your hands around Ellie’s neck and tried to throttle her.”
The Judge continued: "She tried desperately to fight back, scratching at your neck in the process. You did not have the sense, or the decency, to stop. Instead, you picked up a kitchen knife.
“You then carried out the most appalling attack on this defenceless girl, repeatedly stabbing her to the face and neck.
“The pain and terror she must have suffered in her last moments, as your frenzied knife attack continued, is beyond imagining.
“First, and most chillingly, you left Ellie on the floor with the knife embedded in her throat and her left hand around the handle of the knife.
“I have no doubt that you arranged the scene in order that it would appear to those who found Ellie that she had been killed, not by another person, but instead by her own hand or in some terrible accident.”
Speaking of the moment Ellie's father found her in a "pool of her own blood", the judge said: "She was stiff and cold and entirely beyond saving.”
"The effect of your actions has not only been to snuff out the life of this bright, intelligent, talented and vivacious young woman with her whole life before her, but also to wreak misery and heartbreak on her family and friends.”
On the day of the murder, Griffiths had been driven to school but he caught a bus home before driving to Ellie's house where he claimed they began revising together. Although, no books or folders were found at the scene.
“Griffiths became angry, perhaps by Ellie’s continued rejection of him, and he attacked her,” said Richard Smith QC prosecuting during the hearing.
A post-mortem examination found Ellie had been incapacitated by pressure to her neck and was then stabbed 13 times in her neck.
She is believed to have fought for her life during the killing in which Griffith's used a knife taken from the Gould's family kitchen.
Griffiths then tried to hide what he had done, cleaning the murder scene with cloths he later hid in a wood near his home.
He attempted to make it look like Ellie had stabbed herself by placing her hand on the knife and text a friend from her phone telling them she wasn't coming to school.
Matthew Gould, Ellie's dad, was the one to find his daughter and said the image of Ellie "faced down in a pool of blood, with the knife in her neck" had haunted him ever since.
Wiltshire Police arrested Griffiths outside his friend's house three hours after Ellie’s body was discovered at about 3.15pm on May 3.
He “lied repeatedly” to police, Mr Smith and denied any knowledge of the crime.
Sasha Wass QC, representing Griffiths, said he was an exceptional student who had been made a prefect shortly before the murder.
She added both families had been "devastated" by what Griffiths had done
In a letter to the court, Griffiths said he expressed "heartfelt remorse" and claimed his "mental health was not good" at the time.
“I’m so sorry. I know my apologies and explanations will never be enough but I hope in time I can show how truly sorry I am," he wrote.
As Griffith’s letter was read to the court, Ellie’s mother Carole Gould stared at him and shook her head.
His parents, who were sat near the dock, wept through the proceedings, as did their son.
Ellie's mum Carol Gould said in a victim impact statement read to the court that her daughter's "cold hand" was something no parent should have to experience. Adding she feels: “helpless, empty and bitter” knowing she welcomed him into their home.
As an A-Level student, Ellie attended Hardenhuish School in Chippenham before she was attacked.
Described as "fun-loving and a joy to be around" by her family.
Judge Peter Blair QC, the Recorder of Bristol, lifted reporting restrictions that prevented the media from identifying Griffiths.
He said the teenager had committed an “extremely grave crime”.
Wiltshire Police officers were able to quickly identify and arrest Griffiths after Ellie’s body was discovered.
The teenager initially denied having seen Ellie that day, or in the days before her death.
In a tribute issued after her death, Ellie’s family said: "We would like Ellie to be remembered as a kind, caring young lady with a wonderful, fun personality.”
Lisa Percy, headteacher of Hardenhuish School, said pupils and staff had been left “absolutely devastated” by the murder.