Extremist Sudesh Amman who injured three people in Sunday's Streatham knife attack struck gangster-style poses as a schoolboy and vowed to "be a terrorist" when he grew up.

Former classmates of the 20-year-old said he was a 'weird' loner, regularly smoked cannabis and was obsessed with knives, as well as claiming to carry grenades.

He was shot dead just weeks after being released early from Belmarsh Prison after being convicted of possessing and distributing terrorist documents in December 2018.

And days before the rampage, the Call of Duty-obsessed gamer had apparently asked his mum to cook him mutton biryani - his favourite dish, reports the Daily Mail.

A notepad found by police during a search prior to him going to prison listed his main ambition to "die as a martyr" and he had supposedly encouraged his girlfriend to kill her parents.

Sudesh Amman was shot dead by police on Sunday in south London (
Image:
PA)

Amman was staying at a bail hostel near to where he launched his attack in south London and had spent the days before praying.

His distraught mum, Haleema Khan struggled to hold back her tears as she described her son as a "nice, polite boy" and "always smiling" following his horrific attack - and only knew of the incident when seeing it on TV, reports the Mail.

The 41-year-old visited Amman at his Streatham hostel on Thursday and said: "He was fine when I went to see him.

"He said, 'Mum, I want some biryani ... your mutton biryani.'”

"He became more religious inside prison, that’s where I think he became radicalised.

"He was watching and listening to things online which brainwashed him. Before he went to prison he was not that religious. After he came out he was really religious."

The mum, from Dunstable, Bedfordshire, went on to say: "He was a polite, kind, lovely boy. I’m so upset, he was only 20-years-old. I saw it on the TV – that’s when I knew it was him.

"His name was there. That was the first time I heard."

Female classmates of Amman told the Mail they recalled him having a dark side and said he used the username ‘StrangerToThisWorld’ online.

One said: "He kept on saying, “I am going to bomb you”. He said: 'I have got a grenade in my pocket and if you take one step closer to me I am going to set it off.'

Streatham terrorist Sudesh Amman grew up in a chaotic household, neighbours have said

"We thought he was joking, but he kept on saying it.

"He said: “When I grow up I am going to be a terrorist.'"

Another said he was "weird" and would regular smoke marijuana, skip lessons and turn up in a dirty uniform.

Now 20, the former classmate at Park High School in Stanmore, said there were "loads of red flags" in regards to Amman's future as an extremist.

She described him "always in the garden smoking weed" at parties and he rarely spoke to classmates.

"In hindsight there were loads of red flags that he was capable of something like this," she said.

"He was very weird and everyone thought he was strange. He stuck out like a sore thumb.

"He was always smoking weed and would skip school to do it or bunk off during the day to smoke it. He spent so much time in isolation because of how rude he was to teachers or for bunking school.

"His skin was never clean and his school clothes were always dirty.

The scene in Streatham where police shot a knifeman dead in the street (
Image:
SWNS)

"His crowd were the weird kids, just different to everyone."

She added: "He was obsessed with knives. He loved them, all types, and he would have pictures of them on his phone and he would always talk about buying them on the dark web.

"He would bring some in his rucksack to school and show some of us sometimes – and always talk about them in detail."

Amman was born in the final week before the new millennium in 1999 at Northwick Park Hospital in Brent, north-west London.

Dad Faraz Khan, 44, was unemployed and said to have been a heavy drinker and womaniser, while his kids grew up in a chaotic household, sleeping in metal bunkbeds.

Mum Mrs Khan raised the children alone, with social services involved, after Mr Khan fled to native Sri Lanka with another woman, sources claim, reports the Mail.

Neighbour, John Leeming, 71, said Mr Khan was never around and the family "was a bit dirty", while another said they were "noisy" and there were regular fights inside the "smashed up" house.

"I used to see him go to the mosque. Before that he was all right and he started going there and he kind of changed, you could see it in him," they added.

Man later named as Sudesh Amman is shot dead by undercover armed police officers on Streatham High Road in south London after he attacked people with a knife (
Image:
Copyright unknown)

However, their next door neighbour described them as a "lovely family" and she described Amman, who also attended Kenmore Park Junior School, as polite.

Another former classmate told the Mail: "He was a very mysterious guy. He was very quiet and didn’t speak to many people. There was always just something odd about him."

After leaving school, Amman went on to read maths and science at North West London College.

At the age of 17 he was then convicted of possessing an offensive weapon and possession of cannabis in 2017, and he was given referral orders.

He began to go under pseudonyms such as Abu Malik on his Xbox as he tried to get in with jihadis online.

Dutch blogger Mark Van Den Berg reported Amman's aggressive online conversations to UK intelligence services, claiming he was wanted to play COD in "real life".

The blogger took screenshots showing Amman having posted an image of a jihadi black flag alongside another of him with a cache of weapons.

It is understood Amman tried to recruit his brothers, aged 11 and 15, into his extremist ideology, taking photos of them with the Islamic State flag and with air guns and giving the IS salute.

He had shared an Al Qaeda magazine in a family WhatsApp group titled 'La Familia' and described radicalisation as "not wasting time".

He was arrested in May 2018 after Mr Van Den Berg's tip-off, with officers finding a cache of propaganda on his PC and phone.

They found manuals detailing killing techniques and the notepad with his life goals, including "partying" with his family in Jannah - meaning paradise.

Police on the scene on the scene of the knife attack on Sunday (
Image:
SWNS)

In December 2018 he was jailed for 13 terror offences and waved to his mum and brothers as he was led out of the Old Bailey, having refused to stand for the judge and laughing during the trial.

His 21-year-old girlfriend, who Amman had encouraged to kill her Christian parents, told the Mail their relationship was "one of the worst experiences of my life".

She said: "This has affected me tremendously. It is something I have been trying to get over. I have completely erased him from my mind. As far as I’m concerned I don’t know him.

"This alone has been one of the worst experiences of my life.

"What normal human being would do something like that? It’s disgusting."

Amman’s mum moved from Harrow to a rented property in Dunstable in 2019, said her son was radicalised during his time in prison.

She said: "He wasn’t even a very devoted Muslim. He got into all this on the internet, but when he went to prison something happened to him."

The Mail reports a Whitehall source said Amman did not attend any de-radicalisation courses inside and associated with extremists.

He had arrived at the bail house, near several schools, on licence from prison, having served less than half his jail term.

The site manager, named Carl, told the Mail Amman prayed "a lot" while he was living at the hostel.