Two more arrests made as British police focus on Westminster attacker's path to radicalization

British police investigating the terror attack in London said Friday that they’ve made two more “significant” arrests as they work to piece together the attacker’s networks and path to radicalization.

The arrests bring the total number of people in police custody to nine, with one woman having been released on bail. Most of the arrests have been in Birmingham, a city in the West Midlands where the suspect Khalid Masood is believed to have been living most recently, and which has a history of issues with radicalization.

During searches of 21 addresses around the country, including five that are ongoing, police have seized 2,700 items, including “massive amounts” of computer data, Britain’s top counter-terror police officer, Acting Deputy Commissioner Mark Rowley said Friday.

“The main line of our investigation is what led him to be radicalized – was it through influences in a community, influences from overseas, or through online propaganda?” he said.

While there was no evidence of further threats, Rowley said, “you will understand our determination is to find out if either he acted totally alone, inspired perhaps by terrorist propaganda, or if others encouraged, supported or directed him.”

In a tweet by the Islamic state group-affiliated Amaq news agency Thursday, the terror group hailed the British-born attacker – who went by several aliases but was born Adrian Russell Ajao – as a “soldier of the Islamic State.” The claim, which failed to name the attacker or provide specifics of any connection, was in line with its past claims of attacks that have been inspired, rather than ordered by the terror group.

The number of victims killed in Wednesday’s attack rose to four, it was announced Friday, after one of the critically injured victims was taken off life support in hospital on Thursday night. He was named as Leslie Rhodes, a 75-year-old retired window cleaner from London.

The other victims were policeman Keith Palmer and college administrator Aysha Frade, both British, and American tourist Kurt Cochran. Fifty others were injured as the attacker plowed his vehicle through crowds walking along Westminster Bridge; two are in critical condition, while another has life-threatening injuries, Rowley said.

Further details began to emerge about the 52-year-old attacker Friday, including the first photograph of him from his schooldays in Tunbridge Wells – a well-to-do town in southeast England – and more insight about his criminal history, which included convictions for grievous bodily harm, possession of offensive weapons, and public order offenses. Prime Minister Theresa May said Thursday that Masood had been investigated by MI5 in the past for violent extremism, but had been considered “a peripheral figure.”

A report in the Brighton Argus newspaper from 2000 details how Masood, then known as Adrian Elms, was jailed for two years for slashing a man’s face in a pub car park, leaving the victim needing 20 stitches.

Adrian Baker, a local in the town where the attack took place, told the Press Association that he remembered Masood as a troubled individual who “didn’t appear to be very religious. He would go into the local pubs.”

Sky News spoke to the hotel manager in Brighton where Masood stayed the night before the attack, who described him as “friendly, laughing and joking” during his interactions with staff.

Thousands of people gathered in central London Thursday night, just a few minutes from the scene of the attack at the British Parliament, for a vigil to commemorate the victims.

“We come together as Londoners tonight to remember those who have lost their lives and all those affected by the horrific attack yesterday. But also to send a clear message, Londoners will never be cowed by terrorism,” London Mayor Sadiq Khan said.

“Those evil and twisted individuals who try to destroy our shared way of life will never succeed.”