That's not true. Our police can and do use lethal force on criminals. It's just that when they do so, it needs to be justified. The trigger of these riots was bad PR following such an incident. (Which may have been justified; it's too early to say. There were early reports that one policeman had been shot, and would have died had the bullet not hit his radio. Forensic evidence showed that the bullet came from a police gun, and the criminal appears not to have fired a shot. Investigations are on-going. It doesn't help that the police have a history of cover-ups after such incidents, and the public don't automatically believe the police account.)

These riots got out of control largely because the police weren't prepared for them, because we've not had anything like it for a generation. It's probably a good thing that the rioters weren't armed with guns.

Homeowners can legally use lethal force defensively in the UK. This has been tested in the courts time after time. What we can't do is chase a burglar down the street and then shoot him in the back.