Islamic State fanatic Matthew King has been jailed for life with a minimum term of six years for plotting a terror attack on British police officers or soldiers, after he was filmed scoping out a police and train station.
King, from Wickford in Essex, previously pleaded guilty to preparation of terrorist acts between December 22 2021 and penipu May 17 2022.
The 19-year-old carried out surveillance at police stations, railway stations, a magistrates' court and a British Army barracks, and was just one day away from embarking on a terror attack when he was arrested by police last year.
Footage released by police after the sentencing at the Old Bailey shows King walking past a train station while dressed in a black tracksuit and cap, as well as filming a police officer from behind on a platform.
In mitigation, his barrister Hossein Zahir KC said King was 'immature' and the prospect he would have carried out a terror attack in the UK or travelled to Syria to join the so-called Islamic State was 'remote'.
But Judge Mark Lucraft KC told the 19-year-old he poses a risk to the public, and revealed a phone call made by King to his mother after being arrested in which he claimed to have done 'nothing wrong'.
Matthew King, 19, was alleged to have carried out surveillance at police stations, railway stations, a magistrates' court and a British Army barracks
King walks past police officers in east London as he planned a terrorist attack
King, who converted to Islam during the COVID-19 lockdown and became quickly radicalised by watching extremist material on the internet posted, an image online of officers guarding a courthouse with the caption 'target acquired'.
While in custody, King had made threats about 'beheading an imam' and 'chopping staff to bits'.
Sentencing, Judge Mark Lucraft told King: 'It is clear you are someone who had developed an entrenched Islamist extremist mindset, extreme anti-western views and you intended to commit terrorist acts both abroad and overseas.
'Your intention was not merely transitory but one which you had become settled on for a period of six months.
'Having reflected on the danger to the public you pose, there must in my view be a discretionary life sentence.
'The risks around you are clear and concerning.
You will say some things to a professional and contrary to others meaning there is no clear picture of when those risks may abate.'
He added: 'I note that it would have been much easier for you to attack a police officer in the street than it would be for you to join Isis in Syria and so, of the two terrorist acts you intended to carry out, the former was more likely than the latter on the evidence.'
Setting out aggravating factors, the judge said King was 'motivated by hostility towards non-believers', was in contact with other extremists, used aliases to hide his identity, and failed to heed warnings from his family and others in mosques.
King had also discussed a desire to torture and kill a US or British soldier, said Commander Dominic Murphy, head of London police's Counter Terrorism Command, saying the speed of King's self-radicalisation was striking.
Asked if police had arrested him just in time when they swooped in May last year, Commander Murphy agreed.
'I'm pretty happy to say it was imminent,' he said.
'It's very clear to us that King was planning and had a firm intention and desire to carry out a terrorist attack.'
Police said they were alerted in April 2022 to the teenager, who lived with his mother and two sisters in Essex, northeast of London, by calls from several people who had become alarmed at his increasingly overt extremist behaviour.
Judge Lucraft praised King's mother, saying: 'She took the very bold step of alerting Prevent when she had concerns for her son. That cannot have been an easy thing to do in the first place and in my view she [did] absolutely the right thing.