Counter-terror police are leading the investigation into the attack. In a statement on Friday night, the Metropolitan Police said the investigation has "revealed a potential motivation linked to Islamist extremism".
... the Metropolitan police said the senior national coordinator for counter-terrorism policing, Deputy Assistant Commissioner Dean Haydon, had formally declared the incident as terrorism. The early investigation has revealed “a potential motivation linked to Islamist extremism”, the force said.
As part of the investigation, officers are searching two addresses in the London area, the Met said. The force believe the man acted alone and are not seeking anyone else at the moment.
Essex police had briefed counter-terrorism policing headquarters about details of the attack and suspect throughout Friday afternoon. MI5, the domestic Security Service, was also monitoring the investigation.
Officers are carrying out searches at two addresses in the London area and police said they believed the attacker acted alone.
Sources have told the Guardian he has the same details as someone who had previously been referred to the Prevent scheme, the official programme for those thought at risk of radicalisation.
While surgeons began trying to save Sir David's life, the attacker was arrested and handcuffed by armed officers. An eyewitness described him as appearing calm and compliant as he was led away. It is understood he was not shouting any Islamist slogans during the incident, and it was thought the attack came without warning.
It is understood Sir David's surgeries have been disrupted in the past by a number of protests about a range of issues. It is unclear whether the police were ever informed about any incidents or threats arising from the demonstrations. The Telegraph understands that Essex Police have asked permission to access Sir David's parliamentary casework as part of the investigation to see whether anything he had been working on might explain the tragedy.
The attacker is in custody at an Essex Police station.
I read that Sir David was the Chair of Conservative Friends of Israel. If true (I have not checked it), I would say that is sufficient motivation in itself.
Sue - It's certainly what that charming specimen Anjem Choudary gives as the likely reason. I can't put the link here. I'll make it part of my next post. Or you could look in the Daily Mail and do a search if it has slipped down the headlines