LONDON - More than a week after a British soldier was killed in broad daylight on a London street in an apparent Islamist-motivated attack, one of the suspects has been charged with murder. The other is still recovering in the hospital after being shot by police. Authorities are trying to piece together how two British citizens - who were both known to security services - allegedly went on to commit such a brutal attack.

In the days since the killing, it's emerged that one of the suspects, Michael Adebolajo, was arrested in Kenya in 2010, accused of seeking training with terror group al-Shabab in neighboring Somalia. In video of the court appearance, he makes this accusation against the Kenyan authorities.

"These people are mistreating us, we are innocent, believe me," said Adebolajo.

Extremist views

Adebolajo was then deported back to Britain. Earlier images have surfaced of Adebolajo attending an Islamist demonstration in London in 2007. A picture is emerging of young men radicalized on the streets and on the Internet, said terror expert Brooke Rogers of Kings College London.

"It's really difficult to understand when somebody's going to move from just talking about things online, attending this type of legal rally, espousing more extremist views publicly even, it's very difficult to understand when they're going to actually move to the point of violence," said Rogers.

Both suspects attended meetings by the Islamist group al-Muhajiroun, headed by Anjem Choudary. The group burned American flags outside the U.S. Embassy in London on the anniversary of 9/11.

The day after the London attack, Choudary made these remarks.

"If we would withdraw troops from Muslim countries, if we stopped using all of these oppressive measures, then I don't think these things would take place," said Choudary.

Converts to Islam

Similar rhetoric about the occupation of Muslim lands was used by the suspects at the time of the attack.

"I thought that was quite interesting because they were British citizens, so identifying with 'our lands' - I think we all know they mean... The rhetoric is simple, pure engagement, either in these groups where these discussions are taking place - Islamist influenced - or in the chat rooms, on the websites," said terror expert Rogers.

Both suspects were converts to Islam. Robin Simcox of The Henry Jackson Society policy institute said a disproportionate number of terror offenses in Britain were carried out by converts.

"They feel as if their lives have made the wrong path. And religion has almost been a way out for them initially. And then eventually, with some individuals, it's led to them following more extremist interpretations," said Simcox.

The London attack has reignited calls for radical Muslim preachers to be banned.

"Someone who isn't breaking the law, but is very clearly radicalizing individuals and giving them extremist interpretations of faith, is an extremely difficult problem to try to face up to," said Simcox.

Analysts say that as the investigation reveals new details, the debate between freedom of speech and tackling radicalization is likely to intensify.