The British Teenager Who Tried to Bomb a Tube Train

Three-and-a-half weeks earlier, on the 3rd of May, 2017, Damon had been found guilty of leaving a homemade bomb packed with ball bearings on a Jubilee Line train. Marks knew that whatever decision he made would come under renewed focus after the deaths of 22 people in the shocking and senseless suicide bombing in Manchester just four days before. A few minutes after starting proceedings, he announced there would be a short break and cleared the room.

Outside the court, Antonitza steeled herself for another unbearable stretch of minutes spent worrying about her son. His lawyers had already told her that it would be "a miracle" if he got anything less than ten years. "He needs help, not prison," she told me.

From an early age Damon had been obsessed with computers. He'd spend hours glued to a screen, but then so does everyone. "He lived on his computer, but that's what they do, isn't it?" said Antonitza. "Computer and Xbox Live."

But Damon was also fascinated by weapons. He first tried to build a rudimentary bomb at the age of seven. He owned a blank-firing, self-loading pistol and a BB gun, and made a YouTube video reviewing his "Mustang knife, by Highlander". In the short video, he runs through the knife's technical specs in his high-pitched, childlike voice. "It's got a sharp, stainless steel blade, which is obviously because it's a knife and you're hoping for it to be sharp," he says. "I know it even cut my finger."

His condition and his unusual voice made it difficult for him to make friends, but he was an intelligent student. He got an A* on his Religious Education GCSE, a subject his mum now regrets letting him study. "That's when we bought him a Koran," she said. "I wish we hadn't. That's when he started learning about Islam."

When he won a place at London Metropolitan University to study Computer Forensics last year, he and his mum moved together to Rotherhithe, in south-east London. It was only weeks later that Damon was arrested. Antonitza still finds it hard to believe he could have intended to hurt anyone. "He's such a gentle little boy, wouldn't hurt a fly," she said. "The first thing he said when I went to visit him was: 'It was a prank, mum.'"

WATCH: 'Targeted Individuals', our film about the people who believe they're being controlled or tracked by the government.

But the bomb a ten-19-year-old Damon left on a Jubilee Line train on the morning of the 20th of October last year was not a hoax. It was based on a design that he had found online in the al-Qaeda magazine Inspire after watching footage of the Boston Marathon bombing. The article was called "How To Build a Bomb in the Kitchen of your Mum". The timer – built using a £2 Tesco clock - had worked, and the mechanism had ignited.

It was, as the judge put it, merely "fortuitous" that the mechanism had not in turn lit the explosive powder. If it had done, it would have fired ball bearings out into the carriage. The number injured or killed would have been down to sheer chance, depending on how busy the carriage had been as it approached Stratford.

The backpack containing the bomb that Damon left behind was spotted by passengers, who alerted the driver at Canary Wharf. He assumed it was simply lost property and took it into his cab. On the way to North Greenwich the driver looked inside the bag and saw protruding wires. North Greenwich station was evacuated when the train arrived.

Damon, who had not disguised his face on CCTV and had used his own registered Disabled Persons Oyster, was tasered and arrested the following day near Holloway Road in Islington. When police searched his home and computer they found photos of extremists, including the ringleader of the 2015 Paris attacks. They also discovered shredded bomb making instructions and a shopping list for "pressure cooker bomb materials" on his iPad. It included a reminder to "keep this a secret between me and Allah #InspireTheBelievers".

"He's a stupid boy," said Antonitza. "It's a waste of his young life."

The defence barrister, Richard Carey-Hughes QC, said that he had asked Damon that morning whether he would ever plant another bomb. He said Damon had replied: "No, never. I don't want to be in prison. I'm genuinely sorry people were scared."

Carey-Hughes made reference to the Manchester bombing. "This is a difficult climate to ask for mercy for someone convicted of this type of offence," he acknowledged. "Nevertheless, we do so and we invite my lord to extend mercy. This case is different. It seems unique and so is this young man."

Carey-Hughes described Damon as someone who would inevitably fall through the cracks of the system. As Asperger syndrome is not a treatable condition, he is ineligible to be sent to a medical facility. This means the judge's only option was to send him to prison, where his condition will make him vulnerable. Carey-Hughes raised the concern that Damon could be radicalised during his time inside. There is, he suggested: "No proper place for him."

Speaking before the sentencing, Clare Hughes, the Criminal Justice Coordinator for The National Autistic Society, said that while prison can sometimes be the right option for offenders with autistic disorders like Asperger syndrome, they need to be supported by people who understand the condition. "There are some really positive examples of people going into custody and that being quite a life-changing thing for them," she said. "But it's got to be with people with the knowledge and commitment to provide the autistic individual with the help and support they need. It's really important to have a consistent approach right across the custodial part of the prison as well as education and healthcare. All of them need to work together to get the right outcomes for autistic prisoners."

Hughes also made clear that it would be wrong to link autism with violent acts. "Clearly, the stories that hit the headlines are cases like this," she said. "We don't hear about the millions of autistic people who are just going about their daily lives. It's a tiny percentage of autistic people who commit offences like this. It's absolutely not what's happening for the majority of people, but they don't have a voice."

Antonitza shook as Marks prepared to read her son's sentence. He began by saying that he was satisfied that Damon had not been motivated by a desire to carry out an act of terrorism. The decision not to categorise Damon as a terrorist would be widely mocked later on Twitter, with many arguing he would have been treated differently if his skin were a different colour. This outrage is understandable in a culture that failed to classify even the obviously politically-motivated killing of Jo Cox as a terrorist act, but the decision seems well justified in Damon's case. Psychiatrists agreed he did not intend to make a political statement. Exactly why he did what he did is still hard to fathom. As Marks put it: "Quite what your motives were and what your true thinking was in acting as you did is difficult to discern with any degree of clarity or certainty. Whatever the position, the seriousness of what you did cannot be overstated, not least against the background of the fear in which we all live from the use of bombs here and around the world, an all too timely reminder of which were the events in Manchester earlier this week."

Despite not viewing him as a terrorist, Marks did conclude that Smith must be treated as a dangerous offender. None of the psychiatrists who spoke to Damon could say for certain whether his obsession with explosives would be possible to shake. They could not say he wouldn't try something like this again. Marks told Damon: "I am influenced by your history of preoccupation with weapons and bombs, as well as by your condition, which makes it difficult for you to empathise with others and to understand and fully appreciate the very serious potential consequences of your actions, as this incident amply demonstrates."

Shortly before midday, Marks sentenced Damon to 15 years imprisonment, with an extended period of five years on licence. The sentence will initially be served in a young offender institution, although he's likely to be transferred to a Category A prison when he turns 21.

Antonitza sighed with relief. She had feared a longer sentence.

Her son was escorted from the courtroom by his guards. From the moment Damon left that bag on the train it was almost inevitable he would go to prison. Whether or not he gets the help he needs remains to be seen.

Stepping alone into the bright sunlight outside the Old Bailey, his mum was met only by television cameras.

@KevinEGPerry

More on VICE:

The Story of the Female Serial Killer Who Found Murder 'Moreish'

Speaking to the Teenage Feminists of Twitter Who Are Obsessed with Serial Killers

The Life and Crimes of 'Cannibal Cop Killer' Stefano Brizzi