British police released a photo and further details of Khalid Masood on Friday, as the number of people killed in his ramming and knife attack outside parliament rose to five.
The motivation for Wednesday’s attack is still not clear but a hotel manager who met Masood a few hours before the attack said his manner was jovial.
By Friday police had recovered more than 2,700 pieces of evidence, including “massive amounts of computer data”, and interviewed nearly 3,500 people about Masood’s life and final hours, said Mark Rowley, Scotland Yard’s chief antiterrorism officer. But they have yet to determine whether he had been radicalised, or when.
Two additional arrests were made on Thursday night, in north-west England and in Birmingham, bringing the total number of arrests up to 10.
According to police, Masood, 52, was a black man who was born Adrian Russell Ajao on Christmas Day, 1964 and converted to Islam late in life. He was a father of three who had a string of criminal convictions for physical violence, possessing offensive weapons and breaches of the public order. He was also known in early life as Adrian Elms.
He appears to have been estranged for more than 20 years from his mother and stepfather, Janet and Philip Ajao, who live in Carmarthenshire, west Wales.
Masood and his family moved often over the past five years, first within London and finally to Birmingham. He left his last home in Birmingham at Christmas, and was alone, neighbours said.
The British newspaper The Sun, which claimed to have obtained a copy of Masood's CV, reported that he had spent time in Saudi Arabia in 2005, teaching English.
He had a string of convictions for violent offences and had served time in prison. But Masood’s age, 52, makes him unusual among radicalised would-be perpetrators of terrorist acts.
Masood had stayed in the Preston Park hotel in Brighton, on the south coast of England, on Tuesday night, where the manager, Sabeur Tuomi, remembered him “joking and smiling “ and said he “checked out peacefully.”
The next afternoon, Masood ploughed his rented Hyundai 4X4 into a crowd of pedestrians on Westminster Bridge, killing three and injuring 50. Then, rushing towards the Houses of Parliament with a knife, he stabbed a policeman fatally before being shot.
A fifth victim, a 75-year-old man named Leslie Rhodes who was visiting a nearby hospital, died of his injuries on Friday. Two more of Masood’s victims remain in critical condition in hospital.
The photograph police released on Friday shows Masood as a burly, bald man with a beard. They are still trying to determine establish whether he acted “totally alone inspired by terrorist propaganda” or whether he was supported or directed by other terrorist individuals or groups.
Steve Hewitt, a historian at the University of Birmingham who specialises in security and counter-terrorism, told The National that "thanks to the internet and satellite television," anyone anywhere could now be radicalised, "as a result of issues that have nothing to do with the home environment".
Ever since four British men carried out the deadly July 2005 attacks that killed 56 people in London, British intelligence agencies have maintained “a focus on terrorists who are British as opposed to foreign”, Dr Hewitt said.
Given Britain’s geographic isolation as an island, and given that visitors cannot enter the country on Schengen visas, as on mainland Europe, it is difficult for terrorists to arrive in the UK purely to carry out attacks.
Further, a crackdown on weapons such as firearms and explosives, as well as intense intelligence scrutiny of such weapons, has made it difficult for terrorists to acquire them. As a result, Dr Hewitt said, terrorists have started to realise — as they did in the lorry attacks in Nice and Berlin last year — that “low-tech terrorism against so-called soft targets is just as effective for the cause and much easier to do”.
“One could argue that almost paradoxically it shows that counter-terrorism measures are working,” Dr Hewitt said. “Conversely, the chances of killing as many people [with a car] as in a group attack are not as high. So they are more difficult to stop, but usually not as deadly as an attack carried out by a cell or team.”
Automobile use is impossible to restrict, given the abundance of car-hire agencies across western Europe. Similarly, it is difficult to curtail the movement of vehicles except in high-security zones. This makes it easy for someone like Masood to resort to the low-tech method of driving a car into a crowd of pedestrians.
Learning to drive a car is also a key life skill, rather than a red flag waved to intelligence agencies, as higher-level terror training is.
“For their use to be effective, guns require training, either internally or abroad,” Dr Hewitt said. “Either way, such activities, including going abroad to attend a terrorist camp, are bound to generate suspicions. Bomb making is even more of a complex skill that requires real expertise. In comparison, driving a car is a common activity practised by millions from as far back as their teenage years.”
Such terrorists are “glocal – both global and local,” said Dr Hewitt.
Across the UK, police presence continues to be heightened, with the number of armed officers up by a third.
Mr Rowley also appealed directly to the public for more information.
“We remain keen to hear from anyone who knew Khalid Masood well; understands who his associates were; and can provide us with information about places he has recently visited,” he said.