Suspected would-be suicide bomber Yasin Hassan Omar, who is being questioned by anti-terror police, is a 24-year-old Somalian who has been in the UK for more than ten years.
Omar was felled with a Taser stun gun when officers stormed the house where he was hiding in Birmingham yesterday morning.
He is the first of the July 21 suicide squad suspects to be caught after an apparent failed attempt to blow up a Tube train near Warren Street station in central London last Thursday.
He arrived from Somalia at the age of 12 as a refugee with relatives and in May 2000 was granted indefinite leave to remain in the UK.
He and one of his alleged accomplices, Muktar Said-Ibrahim, are thought to have been staying at a flat on the ninth floor of a tower block in New Southgate, north London.
Omar was the registered tenant there for the last six years and during that time he was paid up to £24,000 in housing benefit.
Said-Ibrahim, aged 27, is a convicted violent criminal who was part of a teenage gang which carried out a string of muggings.
Friends said that as a youngster he smoked cannabis and was known as a troublemaker but he was radicalised during his time in jail.
He was sentenced to five years in early 1996 but qualified for early release in 1998 after serving two and a half years at Huntercombe Young Offenders' Institution and Woodhill Prison.
When he came out he grew a beard, adopted Islamic dress and became very devout.
Said-Ibrahim had arrived in the UK from Eritrea in east Africa as a child refugee with his family in 1992 when he was 14. He attended Canons Hill school in Edgware.
In November 2003 he applied to become a British citizen and he was given a British passport last September.
A condition for naturalisation is being of "good character" and the Home Office was unable to comment on how Said-Ibrahim was able to obtain a British passport despite a criminal record.
Last night, the Home Office revealed that Jean Charles de Menezes's student visa had expired more than two years before he was shot by police.
The Government also issued a statement which appeared to indicate Mr de Menezes had a forged stamp in his passport.
A Government spokeswoman said: "We have seen a copy of Mr de Menezes' passport containing a stamp apparently giving him indefinite leave to remain in the United Kingdom.
"On investigation, this stamp was not one that was in use by the Immigration and Nationality Directorate on the date given.