London: A troubled British teenager who threw a six-year-old French boy from a viewing platform at London's Tate Modern art gallery was on Friday jailed for life.
Judge Maura McGowan told Jonty Bravery, 18, he would spend at least 15 years in custody for attempting to murder the boy in front of horrified crowds on August 4 last year.
But she also said: "You may never be released."
The young boy, who cannot be identified because of his age, was hurled head first off the 10th floor gantry and plunged 30 metres (100 feet) on to a fifth-floor roof below.
He broke his spine, legs and arms and suffered a head injury in the fall. His condition has since improved but he still requires round-the-clock care and may never fully recover.
Sentencing Bravery at the Central Criminal Court judge McGowan said what he had done was "callous" and "beyond imagination".
She told him he would remain "a grave danger to the public", adding: "You almost killed that six-year-old boy... The injuries you caused are horrific.
"That little boy has suffered permanent and life-changing injuries."
'I am mad'
Bravery has been detained in a high-security psychiatric unit since the attack, which he said he carried out because he had not been given proper treatment for mental health issues.
The burly teenager, who was 17 at the time, was diagnosed with Autism Spectrum Disorder (ASD) at the age of five and has a personality disorder.
Psychiatrists said he also had psychopathic traits, although he had not been formally assessed for the condition.
When challenged about what he had done on the day of the attack, he is said to have smirked and replied: "Yes, I am mad... It's not my fault. It's social services' fault."
Questions have been raised about how he was able to carry out the attack, as he was living in supported accommodation and under the care of social services in west London.
The court was told he had also indicated he would carry out such an attack, in a secret recording purported to have been made by his carers that was never shared.
A forensic consultant psychiatrist told the court on Thursday it was unlikely Bravery would ever be considered for release into the community.
Judge McGowan said she had weighed the submissions of medical experts in the case, and concluded that he would not get more treatment in a secure unit than in prison.
She reduced the sentence because of his age and his early guilty plea.
But she told him: "I cannot emphasise too clearly that this is not a 15-year sentence. The sentence is detention for life. The minimum term is 15 years.
"Your release cannot be considered before then. You may never be released."
Bravery, who followed proceedings via videolink, showed no emotion as the sentence was passed.