20 December 2011 Last updated at 11:23
Some 299 officers were injured during the five nights of violence in England
Police should be given clear rules about when they can use water cannon and plastic bullets against rioters, a watchdog has said.
But officers could lawfully have shot arsonists in some cases during the summer rioting in England, the Inspectorate of Constabulary said.
Water canon and plastic bullets could have been used in a “number of real scenarios”, its report said.
MPs have said such tactics would have been “indiscriminate and dangerous”.
In its review of the August riots, the inspectorate said a new framework for public disorder was needed.
It said water cannon and plastic bullets could be considered to deal with rioters throwing missiles and petrol bombs, to stop “violent attacks on the public” and arson attacks, and also where fire and ambulance crews were under threat.
Firearms can “potentially” be deployed where arson poses a threat to life, or of serious injury, legal advice in the report states.
The report said water cannon were an “effective means of dispersal and incur fewer injuries to the public” in static and slow-moving scenarios.
But it conceded there were none on mainland UK, they cost more than £1m each and need to be deployed in pairs to be effective.
The inspectorate also revealed that discussions had taken place about support the military could provide in any future disorder, suggesting the Army could help in “logistical roles”.
The inspectorate added that its own public opinion survey suggested people support the idea of using water cannon and plastic bullets in public order situations.
The review is the latest in a number of reports into the riots and its causes.
On Monday, a Commons Home Affairs Committee report said the policing operation to tackle the summer riots across England was flawed.
The Policing Large Scale Disorder: Lessons from the disturbances of August 2011 said insufficient numbers of officers were initially deployed and police public disorder training was inadequate.
The perception that in some areas police had lost control of the streets was the most important reason disorder spread, it said, adding that flooding the streets with officers was what ultimately quelled the disorder.
But committee chairman Keith Vaz MP said he did not feel water cannon would have helped police in the riots and may have caused “even greater disorders”.
The Metropolitan Police said it had outlined what it was doing to improve.
Riots broke out in Tottenham, north London, on 6 August, two days after the fatal shooting by police of 29-year-old Mark Duggan. Unrest spread across London and to other cities, including Manchester, Birmingham and Bristol over the following days.