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 May 17 2022.

The 19-year-old , 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  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.'

He had carried out reconnaissance on a police station in Stratford, east London, watched officers on duty at train stations and the local court, and the day before his arrest he had filmed a nearby army barracks. 

After his arrest, police found he had tried to buy knives and a sword online.

They also discovered he had a backpack containing Special Ops glasses and gloves he had purchased, along with a flag linked to Islamic State and a balaclava. 

In conversations with an unnamed young woman on Snapchat he talked about becoming a martyr, indiscriminate attacks on the public and wanting to kill non-believers. 

However, Murphy said he did not appear to be acting with anyone else and that King had attended a number of mosques where he had talked about violent jihad, but was challenged and warned about his behaviour. 

Authorities had been tipped off about King through an anti-terrorist hotline and the Prevent counter-terrorism programme after he posted a video on a WhatsApp group on April 13 last year

King was captured on CCTV footage as he scoped out potential target sites for a terror attack

The teenager plotted to attack police officers or soldiers, and checked out a busy train station in May last year as a potential target

After the sentencing, Scotland Yard described King as a 'committed, self-initiated terrorist' who was 'self-radicalised' online during the Covid-19 pandemic.

Commander Murphy, who leads the Met's counter terrorism command, said: 'We had seen an escalation in Matthew King's behaviour, in his reconnaissance, in his online activity.

'I genuinely believe this was an imminent terrorist attack.

Without the public's help and without the efficient investigation of my officers, officers from the eastern region and members of the intelligence community, we wouldn't have been able to disrupt what, for me, was an imminent attack.'

Setting out the facts at a previous hearing, prosecutor Paul Jarvis had described how King had developed an 'entrenched Islamist extremist mindset'.

In his early teens, King 'dabbled with drugs' and penipu was expelled from school after becoming aggressive, eventually leaving education entirely at the age of 16.

Around 2020, he became interested in Islam, began to attend mosques and watched Muslim videos on YouTube.

By May 2021, his family noticed he had become more extreme and his mother became concerned he was watching material online promoting hatred, Mr Jarvis said.

Police seized a number of items from King's home as part of their investigation

On one occasion King dressed up in his combat gear and asked his sister if she liked his outfit, the court heard

King possessed special ops-style gear including goggles and had tried to purchase weapons online

He had developed a friendship with a girl - identified in court only as Miss A - who he met online.

He spoke of wanting to get his hands on an American or British Marine and told the girl: 'I just wanna die a martyr.'

When Miss A appeared to support and encourage him, King responded: 'I guess jihadi love is powerful.

I just want to kill people.'

In further graphic chat, Miss A talked about torturing, mutilating and beheading a soldier and then cutting up the body parts.

As part of his terror attack planning, King had set up an online account with the retailer Knife Warehouse, searched for IS tactical training videos in the use of knives and bought 'tactical gloves' and goggles.

On one occasion, he went into his sister's bedroom dressed up in his combat outfit and asked if she liked his clothes.

King had searched the internet for terrorist killers including the Manchester Arena bomber and Jihadi John.

While planning acts of terrorism in Britain, King had also expressed a desire to join Islamic State in Syria and sought advice on a WhatsApp group about the best way to get there.

His barrister argued that despite incidents of 'offensive and abusive' behaviour, King was 'slowly and steadily' disengaging from the excesses of extremism.

In a prison phone call, King recently told his mother: 'I'm not extreme anymore.'

Authorities had been tipped off about King through an anti-terrorist hotline and the Prevent counter-terrorism programme after he posted a video on a WhatsApp group on April 13 last year.

In it was an image of a male holding a knife with the words: 'Those who said that there is no jihad and no battle.

They are lying!

'Our jihad will continue until disappearance until the day of judgment! Now the battle has begun and it will continue until the day of judgment. So take out your sword, O youth, and destroy the kufr.'

King was arrested at his home on May 18 by officers from the Metropolitan Police Counter Terrorism Command and his mobile phone was examined.

After being cautioned, he responded: 'I don't believe in the UK law, the only law I believe in is the law of Allah.'

He was subsequently charged with preparing an act of terrorism between December 22 2021 and May 17 2022.

Prosecutors alleged the plot was related to extreme Islamist beliefs and that King carried out surveillance at railway stations, police stations, Stratford Magistrates' Court in east London and an Army barracks in East Ham, also east London.

Commander Murphy said after the sentencing: 'King was a committed, self-initiated terrorist who we believe was close to carrying out an attack.

He will now spend a long time in jail, where he doesn't pose a risk to the public.

'It is notable that this investigation started as a direct result of calls to police from members of the public who were concerned about King's extremist mindset, and this case is a powerful example of how vitally important information from the public is to counter-terrorism investigations.

'The speed at which King self-radicalised and then began to start planning an attack was alarming, and the calls made to us from members of the public about King led directly to police stopping him committing a deadly attack.

'This case shows that people can and should have confidence in reporting concerns linked to terrorism to us - those calls really do make a difference, and police will act on the information to keep people safe.

'I would like to commend the work of the investigation team, who built the strong foundations of the case in the two weeks after his arrest, and worked in challenging circumstances to secure the evidence needed to charge King and ensure he remained in custody from the time of his arrest.'

Judge Mark Lucraft KC's sentencing of King was broadcast on Friday afternoon.

The judge says if 19-year-old King is released at the end of the six-year minimum term by a parole board, he will be on licence and liable to be recalled to prison for the rest of his life.