A 14-year-old boy laughed and ran away after fatally stabbing 12-year-old Ava White, a court has heard.
More than 20 members of Ava’s family and friends were in court for the start of the teenager’s trial at Liverpool Crown Court on Monday, where the defendant, who denies murder, appeared by videolink.
Charlotte Newell QC, prosecuting, said Ava and the defendant had been in the city centre with friends on the evening of November 25 last year and met “by chance encounter”.
The court heard the defendant had been in possession of a flick knife with a 7.5cm blade and had pleaded guilty to having an offensive weapon.
Ms Newell said: “That knife was used to stab Ava, causing her fatal wound.
“That was done after they argued over the fact that he and his group had, without permission, filmed the antics of Ava and others in her group.
“Ava in particular was appalled and angry that they were filming her and was quite insistent that they delete the footage.”
She said Ava and her friends, all aged between 11 and 15, had shared some alcohol and had been “messing around” near the Royal Court Theatre before being told to move on by security staff at about 8.15pm.
They moved to Richmond Street, where the defendant and his friends saw them and he began to film a video which he would later share on Snapchat, Ms Newell said.
Ava and a friend approached the boys and asked them to stop filming and delete the footage, before being joined by more of her friends, including two older boys.
The jury was told the older boys left but the defendant and his friends then “jeered” at Ava, causing her to run towards them.
A 20-second clip showing the stabbing in School Lane was played to court, which showed Ava approach the defendant.
Family members were in tears in the public gallery as the footage was played.
Ms Newell said Ava had approached the defendant but did not “inflict any violence upon him greater than a push, nor did she produce or have any weapon”.
She said the boy’s reaction was not to turn and run or to slap or punch her.
Ms Newell told the court: “Instead it was to thrust a knife into the neck of this unarmed child with what the pathologist was to determine was moderate force, the force of a firm punch.”
She said the defendant now claimed he was acting in self-defence, fearing he would be assaulted or stabbed.
The prosecutor added: “However, his reaction at the time was to smirk, to laugh and to run away, leaving Ava to die whilst he sought to distance himself from his actions.”
The court heard that he “began a conscious cover-up” of the crime, discarding his knife, phone and coat.
Ms Newell said the defendant was arrested shortly after 10pm and was interviewed by police several times over the course of the following three days.
She said: “He did not say in these interviews that he had stabbed Ava in self defence as he says now.
“He told a series of lies about his movements on November 25 and he interspersed those lies with refusals to answer questions at all.
“She said he had claimed he was playing Call of Duty at a friend’s house at the time of the killing and then went on to say another boy had stabbed her.”
Mrs Justice Yip told the jury of eight men and four women that the defendant, who was accompanied by an intermediary, had attention-deficit/hyperactivity disorder and they may see him using a fidget toy to help his concentration.
The defendant also denies an alternative count of manslaughter.
The trial is expected to last three weeks.