An 18-year-old man stabbed his teenage girlfriend repeatedly in the neck in a brutal killing when she dumped him.
Thomas Griffiths admitted murdering 17-year-old Ellie Gould at her home in Calne, Wiltshire, in May, when she ended their relationship.
The next day, Griffiths, then aged 17, went to the schoolgirl’s house, killed her and tried to make it appear she had inflicted the wounds on herself.
Griffiths is being sentenced at Bristol Crown Court.
The packed courtroom heard the night before Griffiths murdered her, Ellie had told friends they had broken up and he had “not taken it well”.
The pair were pupils at Hardenhuish School in Chippenham, had known each other since Year 7, and been in a relationship for three months.
Griffiths walked out of school on the morning of 3 May and drove to Ellie’s home in Springfield Drive.
There he attempted to strangle her, before stabbing her repeatedly in the neck with a knife taken from the kitchen.
A statement was read out in court from Ellie’s father, Matt Gould, who found her lying on the kitchen floor with the knife still in her neck.
He said it was “the most frightening, horrific and saddest scene I have ever experienced” and it “fills my thoughts all day”.
Evidence suggested Griffiths had put Ellie’s hand on the weapon to make it look like she had done it to herself.
The court heard Griffiths spent an hour at the house before he drove home, changed his clothes, and dumped a bag of items taken from Ellie’s house in a wood.
Later that day he sent a series of “fake” messages to friends and to Ellie’s mobile phone asking if she wanted to meet.
Griffiths also told friend marks on his neck were caused by self-harm but the court heard they most likely caused by his “young victim fighting for her life”.