A teenager has been convicted of murder by a jury at Brighton Crown Court for stabbing a 17-year-old boy to death at a party.
The boy, whose identity is protected by law, killed Charlie Cosser when he stabbed him three times in the chest.
The attack happened at an outdoor event called BalFest, attended by about 100 people, at a farmhouse in Warnham, near Horsham, on Saturday 23 July last year.
The defendant was 16 at the time of the murder and has since turned 17. He is expected to be detained at His Majesty’s pleasure – the equivalent of life imprisonment for a young offender.
The jury was unanimous in finding the boy guilty of murder and of having a knife after more than three weeks. The trial started on Monday 13 May.
Members of Charlie Cosser’s family, who have been at court throughout the trial, cried and hugged each other as the verdicts were returned.
The jury was told that a fight started involving the defendant and Charlie and two other boys on the dance floor after the defendant and his friends were asked to leave the party.
Without realising, a girl at the party captured part of the fight on video as she filmed her friends dancing to the Britney Spears song Toxic under disco lights in a marquee.
Alan Gardner, prosecuting, had told the jury: “In the darkness and noise of a crowded dance floor, his use of the knife and blows of the knife went unnoticed by those in the vicinity.
“The defendant stabbed Charlie Cosser with that knife as they came together on the dance floor.”
Jurors heard from several witnesses who were at the party that night.
A friend of the defendant said that the boy had drunk an “excessive amount” of vodka and appeared “angry” after an older man had unsuccessfully tried to make him leave the party because of his apparent behaviour towards a young woman.
The witness described hearing “arguing” and “shouting” inside the marquee before the defendant and others started fighting.
Later on, the young man found the defendant next to the road with his hands and trousers “covered in blood”.
He told the jury: “The top of his joggers down to his knees were almost, like, drenched.”
He and another friend of the defendant also said that they heard the teenager say: “I’ve stabbed someone.”
Other party guests, including Harriet West, described seeing a boy, believed to be Charlie, lying on the ground as she approached a man in hi-vis who was acting as security.
She said: “He didn’t have a T-shirt on and he had blood all over his chest. I just left. The man in the hi-vis was going on to his knees.”
The court heard that Charlie was still conscious when police arrived at 12.30am and was able to tell them his name, address and date of birth.
He suffered a cardiac arrest on the way to hospital, with internal bleeding caused by a cut to his aorta, the main artery from the heart.
The teenager, from Milford, Surrey, also known as “Cheeks”, died two days later, on Monday 25 July.
After the defendant’s arrest, jurors were told that bloodstains on his trainers were tested and found to be his own blood.
The court was also told the defendant accepted that he burned the clothes he was wearing at the party in a firepit in the garden because he said they were covered in his own blood.
The teenager had suffered an injury to his left hand, which the prosecution alleged happened when he was using the knife to stab Charlie.
The knife has never been found.
The boy chose not to give evidence in the trial but denied murdering Charlie and having a bladed article.
He originally pleaded guilty to murder when he first appeared at Lewes Crown Court on Thursday 28 July last year.
But before being sentenced he successfully applied to withdraw his guilty plea, leading to the trial by jury in Brighton.
Charlie’s family previously paid tribute to their most caring, cheeky and loving son and brother who had a “ridiculously silly sense of humour”.
Since his death, they have set up a charity called Charlie’s Promise which is dedicated to fighting knife crime across Surrey and the UK.
Judge Christine Henson is expected to set a date for the defendant to be sentenced this afternoon (Tuesday 4 May).