A teenage Islamic State fanatic has been jailed for life for plotting a terror attack on British police officers, or soldiers after being radicalised online during the pandemic.

Muslim convert, Matthew King, 19, expressed a desire to kill military personnel as he prepared to stake out a British Army barracks in Stratford, east London.

He discussed his plans and shared a “gory fantasy” with an online girlfriend with whom he struck up an adolescent flirtation, the Old Bailey heard.

His desires to launch an attack in Britain or travel to Syria to join so-called Islamic State were thwarted when his mother reported him to the Prevent counter-terrorism programme.

Authorities were also tipped off through an anti-terrorist hotline after he posted a video on a WhatsApp group on April 13 last year.

While in custody, King had made a violent threats to “behead an imam” and “kill and chop up staff”, the court was told.

In January, King, from Wickford in Essex, pleaded guilty to preparation of terrorist acts between December 22 2021 and May 17 2022.

On Friday, he was handed a discretionary life sentence with a minimum term of six years in the first terrorism sentencing in England and Wales to be televised.

Judge Mark Lucraft KC 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 absolutely the right thing.”

Judge Lucraft found that King is a dangerous offender who carries a risk of future harm to the public, despite claims by his barrister that the defendant is on the path to deradicalisation.

He told King: “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.

In mitigation, Hossein Zahir KC said King is “immature” and the prospect that he would carry out either of his terrorist plans is “remote”.

The defence barrister argued that, despite incidents of “offensive and abusive” behaviour in custody, King is “slowly and steadily” disengaging from the excesses of extremism.

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

Commander Dominic 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 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.

He had developed a friendship with a girl – identified in court only as Miss A – whom 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 made videos as he checked out potential targets including Stratford Army barracks, police officers outside Stratford Magistrates’ Court, and at the railway station.

Some of his hostile reconnaissance videos were overlaid with nasheeds – Islamic chants – and he posted on Snapchat: “Target acquired”.

Meanwhile, 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.

Authorities were alerted after King posted on WhatsApp 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!”

King was arrested at his home on May 18 last year by officers from the Metropolitan Police Counter Terrorism Command.

He described his former Islamic name as “Abdul Kalashnikov” and told police: “The only thing which is black and white is the sharia, the law of Allah.”

King’s barrister told the court that more recent conversations with his supportive family showed signs that the defendant is turning away from his radical beliefs.

And in a prison phone call, King told his mother: “I’m not extreme anymore.” (dpa/NAN)

•Jailed teenage terrorist Matthew King

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