Thread by @DdesimoneDaniel

Sudesh Amman, the 20-year-old responsible for the attack in Streatham today, was jailed in December 2018 for 13 terror offences.

I was there and recall Amman smiling as he was sentenced.

He was released from prison around a week ago

He had pleaded guilty in November 2018 to six charges of possessing documents containing terrorist information and seven of disseminating terrorist publications.

One of the terrorist manuals he admitted owning was ‘Bloody Brazilian Knife Fightin’ Techniques’

Amman was first arrested in north London in May 2018 by armed officers on suspicion of planning a terrorist attack.

He had come to the attention of counter terrorism police in April that year when officers were made aware of postings on the Telegram messaging app

The posts included a photo showing an image of a knife along with two firearms on a Shahada flag along with Arabic words meaning: ‘Armed and ready April 3’

The subsequent investigation uncovered a horrifying level of extremism.

Amman had also written of how he was thinking of carrying out a terrorist attack in north London and had conducted reconnaissance.

He also used a family Whatsapp group to spread terrorist material

He sent extremist content to his younger siblings and exclaimed ‘the islamic state is here to stay.’

The chat group included images of Amman’s younger siblings in poses reminiscent of IS supporters

In a separate message Amman said that, as he regarded Yazidi women as slaves, the Quran made it permissible to rape them

In a notebook he had written about his ‘goals in life’.

These included: ‘die as a shuhada’ [martyr] and go to ‘jannah’ [paradise].

Another line said: 'We need the jihad, the jihad doesn't need us'

When he was sentenced, the court heard that much of Amman's fascination with conducting an attack was focused on using a knife but reference was also made to committing acid attacks on mopeds

This blade was recovered by investigators at the time

He sent beheadings videos to his girlfriend and said she should kill her ‘kuffar’ parents

He told her "If you can't make a bomb because family, friends or spies are watching or suspecting you, take a knife, molotov, sound bombs or a car at night and attack the tourists... police and soldiers of taghut, or Western Embassies in every country you are in this planet”

A Dutch blogger is the person who first made officers aware of Amman's postings on Telegram.

The blogger highlighted how the user of concern had linked to a YouTube video of a pro-gay rights speaker who frequented ‘Speakers Corner’ in Hyde Park, London

The post called on others to “all unite together to attack one another. He will be there this Sunday at Hyde Park”.

Police enquiries showed the user of the relevant Telegram account was Amman and a decision was taken to arrest him

This was one of the Telegram posts by Amman that led to the 2018 police investigation

The Dutch blogger whose research triggered the 2018 Met Police inquiry told the BBC he was “shocked” to hear Amman was responsible for what happened.

Azazel van den Berg said he "heard of the attack on Dutch television" but only read about the attacker's identity last night

He added: “I did everything that was possible, I also did not know that man was already free. I think that jihadists like him should be punished harder with prison sentences and not conditionally free with a single bond...

... If he had just served his whole sentence, what happened now would never have happened. But English law must be applied to that, which is a task for the politicians in your country.”