A student from Devon has been found guilty of planting a homemade bomb filled with ball bearings on the tube, after a jury rejected his claim that it was meant to be a prank.

Damon Smith, 20, pleaded guilty to perpetrating a bomb hoax but said he intended the device to work as a smoke bomb to stop the train “for a bit of fun”. He pleaded not guilty to possession of an explosive substance with intent, contrary to the 1883 Explosive Substances Act. He decided not to give evidence at the trial.

Smith has Asperger syndrome and took a keen interest in weapons, which might have been connected to his condition, a jury at the Old Bailey in London heard during his five-day trial. He was also interested in gambling and Islam, and had collected photos of extremists, including the ringleader of the 2015 Paris attacks.

A police photograph showing a component of the device. Photograph: Metropolitan police/PA

Smith was 19 when he left a rucksack containing the bomb on a Jubilee line underground train on the morning of 20 October 2016. Passengers discovered the bomb and alerted the driver, triggering a major security alert. The jury heard that had the bomb worked, it would have detonated as people were being evacuated from North Greenwich station.

Smith was Tasered and arrested near Holloway Road in Islington, north London, the following day. On 22 October, counter-terrorism officers searched his former home in Newton Abbot, Devon, and evacuated nearby properties after they discovered a further possible homemade bomb hidden in the attic.

In his London home, police found weapons including a blank-firing pistol, a BB gun in the shape of a revolver and a knuckleduster. Smith was a fan of weapons and martial arts, and had uploaded videos of himself with the pistol and knife to YouTube.

They also discovered shredded pages of an article titled “Make a bomb in the kitchen of your mom”, from Inspire, a magazine published by an al-Qaida affiliate, and found a shopping list for “pressure cooker bomb materials” on an iPad he used. The note included a reminder to “keep this a secret between me and Allah #InspireTheBelievers”.

But he told officers “he did not hold extremist views and did not agree with extremism … he didn’t want to be a terrorist, what he did was a prank”, Jonathan Rees QC, prosecuting, told the court.

His barrister, Richard Carey-Hughes QC, said though Smith had used Inspire’s blueprint to make the bomb, he had also diverged from it, changing the method of ignition.

CCTV stills of Smith on the platform at Southwark tube station. Photograph: Metropolitan police/PA

“If you’re looking for a bang, you don’t choose something that makes a fizz,” he said, adding that all Smith’s modifications lessened the device’s potential to cause harm.

Smith modelled the bomb so closely on a real device to “persuade the bomb experts that this was indeed a real bomb and thus important and newsworthy”, Carey-Hughes said.

His actions were a progression of his previous “play-acting” with weapons, rather than a “massive and sudden leap into the deep end”, he added.

But an explosives expert told the jury that had the material he used been more finely ground or tightly packed, the bomb’s ignition could have worked.



Rees pointed out that the device was filled with ball bearings, which he said were intended to work as shrapnel, causing injury or even death.



Smith had been fascinated by weapons and bombs from an early age, and first looked up how to make explosives online when he was 10, Rees said. Bombs were “something to do when he was bored”, he told a psychiatrist.

As a teenager, Smith was close to his mother; he had not known his father since childhood. Neighbours said he sometimes stood out. “He didn’t go to mainstream school for a bit because he used to get bullied, because he sounded like a girl,” said one neighbour, Alan Warburton, after his arrest.

When he gained a place at London Metropolitan University to study forensic computing, his mother moved to the capital with him. Smith’s barrister described him as “clinging, as he was, to his mother’s apron strings”.

Smith said he took an interest in Islam, read the Qu’ran and prayed sometimes, but had only been inside a mosque once, on holiday in Turkey with his mother. Police searching his computers found photos of Alan Henning, the aid worker beheaded by Isis, as well as the ringleader of the 2015 Paris attacks, but nothing to connect Smith to any extremist networks. Smith said he thought Islam was “more true” than Christianity on some points, but said he was not an extremist.



Asperger syndrome is an autism spectrum disorder, which in Smith’s case did not impair his intelligence, but can cause intense interest in a narrow range of topics and a lack of empathy.



On the first day of his trial, the judge asked the jury to disregard the fact that Smith was often smiling as he listened to the prosecution outline the case against him. Smith was “acutely aware that he’s presenting himself in a manner that is odd and unsympathetic”, Carey-Hughes said, and on the last full day of his trial, he declined to go into the witness box.



Summing up the case on Wednesday, the judge, Richard Marks QC, told the jury that although they “may feel sympathy with the defendant for his disability ... may feel anger at him for the undoubted stupidity of his actions”, they were to ignore this when deciding if he had intended to endanger life or damage property when he planted the bomb.

Sentencing was deferred until 26 May at the earliest.