Khalid Masood a violent criminal who was regularly on the move

The terrorist who killed three people and injured 29 others in Westminster, London, on Wednesday was a married man who had been living with his family in an inner city suburb of Birmingham, police said.

The attacker, identified by police as Khalid Masood, born in Kent, was also a violent criminal convicted of multiple offences spanning 20 years, said Scotland Yard.

His offences included assaults, grievous bodily harm, possession of offensive weapons and public order offences. He had spent time in jail but not for terrorist-related offences, according to Amber Rudd, the home secretary.

As police began to unravel his complex life it was reported that Masood had a string of aliases and was said have to been born Adrian Elms in Kent in 1964.

He appears to have lived in the south of England – mainly in East Sussex – for many years before moving a number of times to addresses in London and Birmingham.

The 52-year-old’s first conviction was in November 1983 for criminal damage and his last conviction was in December 2003 for possession of a knife, said the Metropolitan police.

It also emerged that Masood had been previously known to MI5 although the prime minister said he had been considered “a peripheral figure” in relation to suspected Islamist terror threats.

He was once investigated in relation to concerns about violent extremism, said Theresa May. Downing Street declined to say whether that was between 2010 and 2016 during May’s time as home secretary. A spokesperson repeated her position that Masood came across the radar of the security services “some years ago”. Since then, there had been no intelligence to suggest his intent to mount a terrorist attack.

The attack, begun shortly after 2.40pm as the Commons was preparing for a vote, was a surprise for some people who knew Masood in Birmingham. He and his family had lived recently in the city, in a three-storey building on the modern Quayside estate about a mile from the city centre. He was described by one neighbour in Winson Green on Thursday as “very calm” and part of a “very reserved family”.

A neighbour, Iwona Romek, a factory worker, said: “He was very calm. I saw the photos on the TV and knew it was the man who lived here.”

Masood regularly wore traditional white Islamic robes, the neighbour said. He had lived in Winson Green for about seven months. One neighbour said he moved out at the end of last year, possibly to a flat above a restaurant on nearby Hagley Road, which was raided by police on Wednesday night.

The flat was just over a mile from an Enterprise Rent-a-Car location where the attacker hired the Hyundai Tucson used to mow down pedestrians, it was reported. “An employee identified the vehicle after seeing the licence plate in an image online,” a source at the rental company said. “We ran another check to verify and immediately contacted the authorities.”

Records suggest Masood had previously lived in Luton, and east London, with a woman, aged 39. Police announced late on Thursday that they had arrested a 39-year-old woman on suspicion of preparation of terrorist acts. It is not known if it is the same person.

The Met confirmed that the raid in Winson Green was part of a wider operation which involved searches of several addresses and eight arrests.

One witness who worked in a shop near the Hagley Road flat said police arrested three men.

Stuart Bailey, 25, another neighbour, said: “There were a load of armed police in the street and on the pavement and I could see three or four in front of me. They were all dressed in black and armed with what looked like MP5s [submachine guns] and one of them had six ammunition magazines strapped to his leg. I wasn’t allowed back in my property for an hour.”

Birmingham city council was unable to confirm or deny reports that Masood had worked as teacher in the city, citing Scotland Yard’s ongoing investigation. There were also reports that he had been a keen bodybuilder.

Romek said Masood’s family moved out of Winson Green a few months ago, and the house was now occupied by new tenants. She added that the man and his family had gone around Christmas, very suddenly, without saying anything. She said: “He was a nice guy. I used to see him outside doing his garden. Never any trouble.”

The property was raided by police on Thursday morning, with a number of officers. “I just heard a lot banging and shouting,” she said. “There was a helicopter above and men in white suits.” In the afternoon a police van remained parked outside the front door.

May, speaking in parliament early on Thursday, said Masood was “not part of the current intelligence picture”. She said: “Our working assumption is that the attacker was inspired by Islamist ideology”. The Guardian understands he was not among the 3,000 Britons on MI5’s list of individuals regarded as potentially capable of committing an act of domestic terrorism.

Shashank Joshi, a senior research fellow at the security thinktank the Royal United Services Institute, said: “We have always known that it is exceptionally hard to understand who will become a terrorist. Masood is unusual in that only a minority become radicalised over the age of 30. His criminal record is unsurprising, as some studies show that a significant proportion of jihadists have had prior convictions.”