In the wake of last month’s Westminster attack, Anders Anglesey examines what drives those who practice or convert to Islam towards the most extreme reading of the faith and in turn commit acts of terror.

The path to radicalisation is complex, multi-layered and attracts vulnerable Muslims from vastly different backgrounds, whether they are criminals or successful students.

Read more: Westminster attacker Khalid Masood killed by single bullet to his chest

Dartford-born Khalid Masood, a convicted criminal who converted to Islam while in Lewes prison in Sussex, killed four people and injured dozens when he drove into pedestrians walking along Westminster Bridge and attacked a police officer with a knife, before he was shot dead within Parliament’s grounds.

He is one of several converts to have carried out acts of terror at home and abroad.

Read more: PROFILE Lee Rigby's killers - Michael Adebolajo and Michael Adebowale

Michael Adebolajo, one of the killers of Fusilier Lee Rigby in Woolwich in May 2013, and Germaine Lindsay, one of the terrorists who carried out the 7/7 London attack in July 2005, were also adherents of extremist interpretations of Islam.

It seems the justice system may be a path toward radicalisation and this is something the Government is acutely aware of.

Adam Deen, a former member of banned Salafist-jihadi organisation Al-Muhajiroun, said practitioners of particular fundamentalist strands of Sunni Islam would target vulnerable people. He said it was not unusual that individuals from different backgrounds have been radicalised.

Mr Deen said: “There is a surge in religiosity across all religions and Islam is no different. It is what type of Islam is out there; in particular puritanical Wahhabism and politically-charged Salafism.

“But the type of Islam that is prevalent in prison is coupled with the gang element and there is a type of pay-off in the form of protection that is offered.

"It is important to consider that these prisoners are vulnerable as well, they have resentment against the establishment and they (fundamentalists) twist that and turn them against society.

“They will tell the prisoner that western society is corrupt and that they would not be considered criminals if they lived under Sharia law. That may have happened to Khalid Masood when he was in jail.”

In light of this, “subversive prisoners” are being moved into specialist units away from other inmates, according to the Ministry of Justice.

A spokeswoman for the MoJ said: “In August last year we announced plans to hold the most subversive extremist prisoners in specialist units.

"Islamist extremism is a danger to society and a threat to public safety — it must be defeated wherever it is found. We are committed to confronting and countering the spread of this poisonous ideology behind bars.

"Preventing the most dangerous extremists from radicalising other prisoners is essential to the safe running of our prisons and fundamental to public protection.”

Last week Frankland jail in Durham was earmarked to become the first prison in the UK to isolate Islamic terrorists from other prisoners.

However, radicalisation has also ensnared its fair share of successful middle-class followers.

Straight-A former-Whitgift and Wallington Grammar School pupil Ahmad Kheder is believed to have become radicalised after he studied medicine at University of Medical Sciences and Technology in the Sundanese capital Khartoum and joined Isis in July 2014.

He was killed when a convoy attempting to leave Isis-controlled Mosul in Iraq was attacked, earlier this year.

Read more: Former Wallington County Grammar School and Whitgift pupil Ahmad Sami Kheder who joined Isis killed in Iraq

The keen football fan was described as a “particularly likeable, good humoured and positive young man” by his teachers at Whitgift.

Kheder’s mother, who did not want to be named, told me she considered her son to be special.

She said: “He was a very special man. I may be biased because I’m his mum, but if you asked his friends on this street they would say it too, that he was a very special man. "

It does not mitigate her feelings towards radical groups and she is adamant people who join Isis should be stripped of their citizenship.

She said: “I read in the newspaper that MPs are discussing targeting British citizens who have gone to Syria without saying if they are medicals, or non-medicals.

“We do understand that people might cause a threat, but rather than discussing targeting them there, which might be a potential for the terrorist in the country, remove their citizenship, stop them from returning.”

Mr Deen commented that it was no surprise Kheder had been radicalised when studying abroad.

He said: “Universities in places such as Sudan, that some young students go to, are in no doubt funded by Wahhabis in Saudi Arabia and because they (young adults) are unexperienced and unequipped to handle the situation they become radicalised.

“They will be told that they are just Muslims and that their only concern should be Islam. That will become their understanding and everything else they learned in the West is in contradiction to that. Islam becomes antithetical to the West.”

In June 2015 the Government published guidance for UK education bodies on how to identify and tackle radicalisation attempts.

The ‘Prevent’ document recommended discussing controversial issues in personal, social and health education lessons where pupils can learn to recognise risk and understand when they are being put under pressure as well as developing effective ways to resist radicalisation attempts.

It also promotes IT policies that aim to keep children safe online and recognise risks posed by extremist and terrorist groups.

The Channel programme, which is part of the 'Prevent' strategy, provides intervention support for recently-targeted people and attempts to build their resilience to radicalisation through workshops.

In light of her son’s death, Kheder’s mother recounts the efforts the family has gone through to get some form of closure.

She said: “We have met the British consulate in Turkey, we have met a lot of people and we have been very open in this profession. Unfortunately, we felt let down and naïve in many ways.”

However, she has found it difficult to believe her son is dead and added other medics had not been killed in the attack on the convoy. 

She says: “There is a picture online, which show both Ahmad and another person are doing in an operation theatre just seven days prior to their death.

“A couple of medics, nothing happened to them, and we were able to talk to their parents. So, how can they say they were bombed, or whatever. It would have killed everyone, not just Ahmad and Hisham (another British ISIS member).

“It’s really hard to believe that.”

To find out more about countering extremism visit Quilliam’s website here. Alternatively, if you are a teacher and are concerned about extremism in your school email counter.extremism@education.gov.uk