A father who claimed his 14-year-old daughter died in a freak accident after innocent horseplay has been found guilty of murdering her by stabbing her in the heart with a kitchen knife.Simon Vickers, 50, claimed he did not know precisely how his daughter, Scarlett Vickers, came to be killed in the family kitchen on a Friday night in July last year.But prosecutors said Vickers was lying and that, “irritated”, he picked up a knife and stabbed Scarlett in the chest.After a 10-day trial, a jury at Teesside crown court in Middlesbrough found Vickers guilty of murder. They rejected his emotional testimony that he would never knowingly harm his only child.The court heard Vickers had smoked a cannabis joint and drunk four glasses of wine at the family home in Darlington on 5 July.He was in the kitchen with Scarlett and her mother, his partner of 27 years, Sarah Hall, when they all started “mucking about”. It began with throwing grapes, became tickling and then nipping with kitchen tongs.In the course of this Scarlett was stabbed, suffering an 11cm wound to her chest. She bled to death at the scene.A forensic pathologist said the nature of the wound meant the knife must have been held.Vickers initially told police that he must have accidentally thrown the knife at her, thinking he had something else in his hand.Giving evidence, he said that was not what had happened and that he may have accidentally swiped the knife along a work surface and it somehow went into her chest.The prosecutor Mark McKone KC said Vickers was lying. “The prosecution submit that Mr Vickers did not and could not have stabbed his daughter through the heart accidentally,” he said.Alcohol, coupled with the throwing of grapes, with some ending on the floor where their dog could eat them, could have led him to become irritated, McKone said.It took the jury 13 hours and 21 minutes to convict him of murder by a majority of 10-2, rather than the less serious alternative of manslaughter.Hall and other family members in the public gallery looked stunned when the verdict was returned. Vickers did not visibly react.Afterwards the Crown Prosecution Service said Vickers’ account of Scarlett’s death was “wholly inconsistent” with the evidence.Durham police said the exact circumstances of Scarlett’s death may never be known but “at about 10.45pm Vickers stabbed Scarlett with a kitchen knife”.Giving evidence Vickers accepted he must have been responsible for the death of Scarlett. But he said he had “no clue” how it had happened. “Why would I harm my own daughter?” he asked. “If someone put a gun to my head and told me to stab her … I would be shot.”He said Scarlett meant everything to him and Hall, who has stood by Vickers and gave evidence in his defence.Vickers told jurors that when he had held Scarlett as a baby after a difficult birth, it was the “best feeling I’ve ever had”.They did everything together as a family, he said, whether that was jumping