One phrase used by neighbors to describe the British-born, Pakistani-rooted London transit bombers is "utterly ordinary."

For the Leeds, England family of one of those bombers, the transition from ordinary young man to killer is inexplicable.

"How could he do anything like this?" said Bashir Ahmed, uncle of Shahzad Tanweer, 22, told reporters Wednesday. "It's unbelievable. I can't believe that."

Tanweer graduated with a degree in sports science at Leeds University. He loved playing cricket; he participated in a long match during his last night on earth.

He also helped out at his family's fish and chip shop. Tanweer had also studied religion during a visit to his parent's homeland Pakistan.

In 2004, police arrested Tanweer for disorderly conduct.

But friends said he was a "good Muslim" and the type of person who could get on with anybody.

The bomb he is suspected of detonating killed seven people between the Aldgate and Liverpool Street subway stations.

Hasib Hussain, 18, also of Leeds, had told his parents he was going to London on July 7 to attend a religious studies seminar. He had become a very devout Muslim after a visit to Pakistan -- the homeland of his parents.

He too was arrested in 2004 for shoplifting and was let off with a caution.

After the bombings, his family -- described by neighbors as very nice people -- called the police and reported him missing.

When police examined a blown-up double-decker bus near London's Tavistock Square, they found remains matching Hussain's description.

They concluded he had been holding the bomb. He became their first suspect. Thirteen died in that explosion.

Security cameras at London's Kings Cross station captured the four of them together, chatting casually and wearing backpacks before heading off in separate directions.

The third suspect was Mohammed Sidique Khan, 30. He wasn't from there, but his wife was. Her mother was a pillar of the community. The two moved there about five months ago from Leeds.

Khan was the father of an eight-month-old girl. He worked with disabled children while his wife teaches.

Seven people died at the Edgware Road subway blast site where his remains were found.

Muslims in the community don't recall seeing him in the local mosques.

A fourth suspect hasn't been publicly identified yet, but the subway bomb he detonated near Russell Station killed 21 people.

Despite Tanweer's and Hussain's brushes with the law, police have described the suspects as "cleanskins," meaning they had no known connection to extremists or conventional criminal records.

For Muslims in Leeds, if not all of Britain's 1.6 million followers of Islam, people sought answers.

"There must be ringleaders working underground who are recruiting and pushing and motivating these young people to commit these atrocities," said Ishtiaq Ahmed of the Bedford Council of Mosques.

Right now, the investigation's focus is to find those ringleaders.

With a report from CTV's Tom Kennedy