A teenager who threw a six-year-old child off a viewing platform at the Tate Modern gallery in London will serve at least 15 years in prison, the Old Bailey was told on Friday. Jonty Bravery pleaded guilty to attempted murder after he picked up the French boy and dropped him over the railings in August last year. The boy was on holiday with his family and survived a 30-metre (100ft) fall, but he sustained life-changing injuries. He suffered a bleed on the brain and various broken bones, and he remains in a wheelchair. He will require round-the-clock care and support until at least 2022. Mrs Justice McGowan said: “The fear he must have experienced and the horror his parents felt are beyond imagination. You intended to kill someone that day. You almost killed that six-year-old boy.” The judge said Bravery’s autism spectrum disorder did not explain the attack, and said he presented “a grave and immediate risk to the public”. “You will spend the greater part if not all of your life detained,” she said. “You may never be released.” Bravery, 18, from Ealing in west London sat impassively with his legs crossed and occasionally placed his hands behind his head while he watched the 20-minute ruling via video link from Broadmoor hospital. The Old Bailey was told that he had been in supported accommodation under the care of Hammersmith and Fulham social services with one-to-one supervision. He had a history of lashing out at staff. Despite his history of violent conduct, Bravery was allowed to leave the home unsupervised for up to four hours at a time. A psychiatrist told the trial he has a mixed personality disorder. The court heard that at the time of the incident, Bravery said he had done it because he had wanted to appear on the television news. Witnesses described him as calm and lacking emotion as he threw the boy over the barrier. They also said he was later heard to say: “It’s not my fault, it’s social services’ fault.” The decision to send Bravery to jail came despite psychiatric experts telling the court he should be detained in a secure hospital. Bravery initially sought to carry out his attack at the Shard, Britain’s tallest building, but baulked at the entry fee. Following his arrest, he was said to have asked police if he was going to be on the news. He said he had been “seriously unhappy” recently and that he had to do anything he could to get out of his accommodation. The prosecutor, Deanna Heer, told the court: “He said he had to prove a point to ‘every idiot’ who had ever said he did not have a mental health problem that he should not be in the community.” He admitted attempted murder at the Old Bailey in December. Bravery later disclosed to a psychiatrist that he had planned the offence well in advance and researched the easiest way to kill someone, narrowing it down to three possibilities: strangling a woman or a child, drowning a child or throwing someone off a tall building. The family of the victim said: “Words cannot express the horror and fear his actions have brought upon us and our son, who now, six months on, is wondering why he’s in hospital. How can he not see in every stranger a potential ‘villain’ who could cause him immense pain and suffering?” No members of the victim’s or Bravery’s family were present in court for the sentencing.