Damon Smith built the device at home with a £2 clock from Tesco after finding an online al Qaida article entitled Make A Bomb In The Kitchen Of Your Mom

The mother of a weapons-obsessed student fascinated by violent extremism who was today jailed for 15 years for planting a home-made bomb on a busy Tube train has leaped to the defence of her 'little boy'.

Former altar boy Damon Smith, 20, built the Manchester-style device at home with a £2 clock from Tesco after finding an online al-Qaeda article entitled Make A Bomb In The Kitchen Of Your Mom before leaving it on a busy tube carriage.

A court heard Smith had been captivated by bombs since the age of 10 and began researching their construction using Islamic State propaganda magazines.

During a trial Smith claimed leaving the bomb on the Jubilee line train was 'just a hoax' but he was found guilty of possession of an explosive substance with intent at the Old Bailey earlier this month.

But today, following his sentencing, his mother Antonitza Smith rushed to defend him, blaming his Asperger's syndrome for his actions and claiming her son was 'just a vulnerable little boy'.

Mrs Smith said: 'Damon's not a killer, he's a good boy. You know he's not a terrorist. He just made a smoke bomb and the prank went wrong.

'He's just a vulnerable little boy who needs a bit of help, not prison. He wouldn't even hurt a fly.'

Despite her comments, the court heard Smith was fascinated by both weaponry and the terror groups Islamic State and al-Qaeda, and created a bomb packed with explosives and deadly ball-bearing shrapnel after reading a terror manual.

But despite this, Smith avoided being charged with terror offences because the authorities were unable to prove he was radicalised.

Today, the autistic defendant smiled in the dock as Judge Richard Marks QC sentenced him to 15 years in a young offenders' institution with an extended period of five years on licence.

Chilling CCTV footage shows the moment Smith steps off the train at London Bridge, with the homemade bomb propped up against the seat by the door

The judge said that although Smith had an interest in Islam, he was not motivated by terrorism.

But he told the defendant: '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.

THREE ON WESTMINSTER COPYCAT CHARGES Three Muslim men were accused yesterday of plotting a deadly copycat attack on Westminster. The trio were allegedly secretly recorded discussing using explosives, guns, knives and vehicles for ‘mass murder’. They are suspected of targeting key sites across London. Vast quantities of extremist material were found on some of their phones, computers and a USB storage fob, and police believe the alleged terror cell was inspired by Khalid Masood, who left four dead on Westminster Bridge before fatally stabbing a police officer in March. Islamic scholar Umar Ahmed Haque, 24, Muhammad Abid, 26, and 18-year-old Abuthaher Mamun were arrested in raids across east London last week. They appeared before Westminster Magistrates’ Court charged with offences under the Terrorism Acts 2000 and 2006. A fourth man, Nadeem Ilyas Patel, 25, appeared alongside them charged with attempting to supply them with a firearm. The men’s lawyers did not apply for bail and Chief Magistrate Emma Arbuthnot remanded them in custody to next appear at the Old Bailey on June 9. Advertisement

'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.'

The court heard on the morning of October 20 last year, Smith, then aged 19, packed a rucksack with explosives and deadly ball-bearing shrapnel as he headed to college in Holloway, north London.

He was caught on CCTV as he travelled on the Jubilee Line, casually flicking through a text book before getting off and leaving the bomb on the floor, timed to go off within minutes.

At least 10 passengers were in the carriage at the time and some of them spotted the abandoned rucksack and alerted the driver.

The driver at first dismissed it as lost property and took it into his cab and carried on towards North Greenwich, jurors were told.

During the journey, he spotted wires coming out of the bag and raised the alarm as he pulled into the station.

Had Smith's bomb worked, it would have exploded just as commuters were being ordered off the platform, the jury heard.

The shrapnel bomb - which thankfully failed to detonate - was similar in design to the deadly device used by Salman Abedi at the Manchester Arena to murder 22 people.

Smith was caught on CCTV exiting London Bridge and heading for a Starbucks on Borough High Street where he took off the hoodie he was wearing and left without buying anything.

The defendant went on to college and, on returning home in the evening, checked the internet for news of what he had done.

When he was arrested the following day on his university campus by armed officers he was carrying a copy of the Quaran in his bag along with his lecture notes.

A photo issued by the Metropolitan Police of one of the components which Damon Smith used to make a home-made bomb using a £2 clock from Tesco

More of the components which Damon Smith used to make a home-made bomb

Upon his arrest by counter-terrorism officers, Smith admitted making the bomb but claimed he only meant it to spew harmless smoke as a Halloween joke.

He told police he had been inspired from watching someone on a YouTube channel called Trollstation doing a bomb prank.

A search of Smith's home in Rotherhithe, south London, revealed his fixation with guns, explosives and other weapons.

Police seized a blank-firing self-loading pistol and a BB gun, both bought legally, as well as a knuckleduster and a knife which he showed off in an online video.

He told police he had been inspired from watching someone on a YouTube channel called Trollstation doing a bomb prank

Police also uncovered torn-off scraps of shredded paper with bomb-making instructions on it and a 'shopping list' of components.

The court heard police also found an image he had made of himself posing with Abdelhamid Abaaoud - the mastermind behind the Paris attacks which killed 130 people - when the killer's picture was shown on TV following the 2015 attacks in France.

Smith told police he was interested in Islam but denied being an extremist even though he posed next to an image of the Brussels-born Islamic terrorist alleged to have masterminded the attacks in Paris in November 2015

In his defence, extracts of a psychiatric report were read out confirming an autism spectrum disorder.

From his bedroom in the Devon town of Newton Abbot, he collected an arsenal of knives and other weaponry, even downloading details of how to make a bomb

He had been interested in bomb-making since the age of 10 and said it was 'something to do when he was bored'.

Smith, who grew up living with his mother in Newton Abbot, Devon, said he had thought about putting a bomb in a park but decided it would be 'more funny' to delay train passengers.

Mitigating, Richard Carey-Hughes QC had said it was a tragic case for Smith and his mother.

He said: 'This is a difficult climate to ask for mercy for someone convicted of this type of offence.

Friends say Smith became obsessed with watching videos of beheadings (pictured posing in a mock execution)

'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.'

The lawyer refuted the suggestion by one psychiatrist that Smith was 'indulging in sadistic fantasy'.

Smith was 'sorry' for the fear and disturbance he caused and has 'learned his lesson', the barrister said.

Mr Carey-Hughes added: 'We asked him this morning 'Would you make another bomb?' and he said 'No, never, I don't want to be in jail'.'

The root cause of Smith's actions were in his autistic disability, he said.

The court heard that experts were divided over Smith's future risk to society.

But Judge Marks pointed out that the defendant, who showed a lack of empathy, had constructed other devices before planting one on the Tube, and concluded that Smith was a dangerous offender.

He told him: '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.'

Smith avoided being charged with terror offences because the authorities were unable to prove he was radicalised.

He always denied holding extremist views but said he read the Quran and was able to quote it at length.

Court artist sketch of Damon Smith, 20,in the dock at Westminster Magistrates Court

A psychologist found Smith had been 'indulging in sadistic fantasies' when he planted the bomb - something the defendant disputed.

The court heard an image of a handgun labelled '2016 Islamic State fighter' was found on his university computer, and he was found to have 'liked' various videos of explosions.

Smith had images of other IS fighters and had searched for an issue of the terror organisation's online magazine Dabiq.

The issue he downloaded featured an article about the bomb which brought down a Russian airliner on 31 October 2015.

Police found the image of him and Abaaoud on an iPad recovered from his grandparent's house.

He told officers that he had been brought up a Christian but thought Islam was 'more true' because the Quran predicted scientific facts like finger prints.

A psychologist found Smith had been 'indulging in sadistic fantasies' when he planted the bomb - something the defendant disputed

Forensic investigators pieced together pages printed from al-Qaeda magazine Inspire found in a shredder, revealing instructions for a pipe bomb called 'Make a bomb in the kitchen of your mom'.

A torn up shopping list was also found with a hand-drawn diagram of an electrical circuit and a shopping list of the ingredients needed for a bomb.

In the loft of his former home in Newton Abbot police found a bag with tape around it containing a battery and protruding wires.

The bag had 'UKIM' printed on it - UK Islamic Mission - and the device was made from a clear plastic jar and contained shrapnel including ball bearings and metal bolts.

Although it looked like a bomb, it was not a viable device, but the entire street had to be evacuated while it was investigated.

But Judge Marks said: 'I don't think it [the bomb on the tube train] was terrorist related although he clearly had an interest in Islam, the evidence doesn't justify that [the offence] was terrorists in nature.'

The court heard Smith moved to London with his mother, Antonitza Smith, to study computer forensics at London Metropolitan University just a few weeks before planting the device.

Forensic investigators pieced together pages printed from al-Qaeda magazine Inspire found in a shredder, revealing instructions for a pipe bomb called 'Make a bomb in the kitchen of your mom'

Smith said he made his first replica pipe bomb aged 14 after reading the Anarchist's Cook Book online

Dr Ian Cummings said in a report: 'He recalled watching the Boston Bombings and downloading the Al Qaeda magazine and visited some Islamic websites.

'He said at the time he didn't think it was an issue - he thought it was just an interest.'

Smith had few friends growing up, and when asked to give a definition of the word he said ' a friend is someone to talk to' before asking 'that's it, isn't it?'.

'He made the device two days before and he decided to put it on a train - he said he initially planned to put it in a park and then thought it would be more fun to put it on a train and 'delay them all',' said Dr Cummings.

'He said he wanted to make a smoke bomb and had no expectation that it might cause harm - he admitted he had used ball bearings but more to give an authentic look than to cause harm.'

Smith did not give evidence at trial, instead jurors were shown YouTube clips he had uploaded of him playing with his collection of aftershaves and giving a tutorial on how to draw Bart Simpson.

Smith said he made his first replica pipe bomb aged 14 after reading the Anarchist's Cook Book

Richard Carey-Hughes QC, for Smith, described him as a 'white boy from Devon' and 'tied to his mother's apron strings'.

His mother, who had been criticised by friends and family in the past for humouring her son's obsession, said it was 'a stupid prank which has ruined his life'.

She added: 'He needs help not prison.'

Commander Dean Haydon, head of the Metropolitan Police's Counter Terrorism Command, said: 'We have seen this week the horrifying impact a bomb can have. And whilst there is no connection between Manchester and Greenwich, it brings into stark reality just how devastating it could have been.

'The bomb Smith made was a viable device, but it failed to detonate, which was our good fortune.

'I would like to praise the public who informed the train driver of the abandoned bag; because of their quick intervention we were able to make it safe and identify Smith.

'At this time of heightened security, we ask everyone to remain calm but alert, to report anything that causes concern immediately; if you have suspicions about someone's behaviour, call police.'