Damon Smith, 20, who is on trial at Old Bailey, claims he left device on Jubilee line train as a prank

A computing student with a keen interest in weapons planted a homemade bomb filled with ball-bearings on the London underground, causing a major security alert last October, a jury has heard.

The court heard that Damon Smith had an interest in Islam, guns and gambling, and collected pictures of extremists including the alleged mastermind of the 2015 Paris terror attacks.

After he was arrested, Smith, 20, who has Asperger’s syndrome, said the device was intended to work as a smoke bomb and had been left as a prank for “a bit of fun”. The prosecution said the device, which had partially detonated, had been designed to endanger lives.

Smith, who was 19 at the time of the incident, is on trial at the Old Bailey charged with possession of an explosive substance with intent, contrary to the Explosive Substances Act 1883. Smith, who wore a navy suit and tie in the dock, denies the charge but has admitted the lesser offence of perpetrating a bomb hoax.



The prosecutor Jonathan Rees QC told the court at the opening of the trial on Wednesday that Smith had intended to build a real bomb “which he intended would explode and endanger the lives of those travelling on the tube train or, at the very least, cause serious damage to the train itself.”

He said CCTV footage showed that on 20 October last year Smith left the bag on a Jubilee line train when he got off at London Bridge at 10.49am. “The CCTV shows that there were at least 10 passengers travelling in the train,” Rees said. Smith then headed to Holloway, where he had started a degree in computer forensics at London Metropolitan University a few weeks earlier.

Passengers spotted the backpack shortly before 11am and alerted the driver, Adrian Clarke, who first thought the bag was lost property and took it into the cabin with him. Clarke looked inside again on his way to North Greenwich station and saw wires protruding from the back of a clock, so he raised the alarm.

When the train arrived at North Greenwich station at 10.56am, it and the station were evacuated.

The device was set to go off at about 11.02am. “Had the device worked, it seems it would have gone off while passengers were being ordered off the platform,” Rees said.

Smith was arrested the following day near Holloway station. A bomb scene examiner noted charring on parts of the device, suggesting it had “partially, if not completely, functioned,” the jury heard.

The device, which was housed in a Thermos flask, had a “quantity of ball bearings, which the prosecution allege had been included to act as shrapnel so as to increase the destructive effect of the device”, Rees said.

The ball bearings were stuck together with PVA glue in a lump weighing almost 500g. In interviews after his arrest, Smith said he had included the ball bearings to “convince people that it was a real bomb”, Rees said. “However, the ball bearings were located in the sealed flask and so were not visible to anyone who looked into the rucksack ... we suggest that the defendant’s explanation for why the ball bearings were included in the device simply doesn’t add up and make sense.”

Smith told officers he hadn’t intended to harm anyone but thought it would be funny to watch “the joke what I did, like making a bit of smoke” on TV. He hadn’t known where he would carry out the prank, he said, beyond “on the tube or something”. He had watched similar pranks on the YouTube channel TrollStation, he said.

The teenager, who was carrying a copy of the Qur’an when he was arrested, and who said he thought Islam was “more true” than Christianity, told officers “he did not hold extremist views and did not agree with extremism, such as the beheadings that were occurring in Syria: they were not Islamic, they were bad ... he didn’t want to be a terrorist, what he did was a prank,” Rees said.

After Smith was arrested, the house in Newton Abbot, Devon, where he had lived with his mother before moving to London, was also searched and a suspicious package was found in the attic. This was found to be a device that looked like an IED but was not viable, the court heard.

The prosecution alleges Smith had a keen interest in guns and other weapons. “This particular interest may have been a function of his autism spectrum disorder,” Rees said. Police found a blank-firing self-loading pistol and a BB gun shaped like a revolver in his London home – both of which he legally owned – as well as a Mustang knife and a knuckleduster.

Smith had posted videos of himself online with his replica pistol and knife, and had “liked” other videos of explosives on social media.

He had searched for a copy of the Isis magazine Dabiq and had saved photos of Abdelhamid Abaaoud, the Belgian-born jihadi who is believed to have masterminded the November 2015 Paris attacks, Rees told the jury.

During a search of his home, police found shredded documents that, when reconstructed, were found to be an article from an al-Qaida in the Arabian Peninsula magazine, headlined: “Make a bomb in the kitchen of your Mom”, showing how to create an IED from everyday items.

The article had annotations that the prosecution alleges were in Smith’s handwriting. An iPad Mini he told police he shared with his mother had a note titled “Pressure cooker bomb materials” dated a month before the incident.

The case continues.