Scotland Yard failed to get enough officers in place quickly enough as the force got its tactics wrong in tackling this summer's riots, Britain's new top police officer has said.
Commissioner Bernard Hogan-Howe said people saw the violence and looting on the streets on the Saturday and thought they could get away with it too.
Mr Hogan-Howe's criticism of the Yard's tactics before he took over two weeks ago came as he added he wanted to make the police more visible on the streets.
The Metropolitan Police was on the back foot during August's riots as it had neither the intelligence on what would happen next or the numbers of officers on the streets to cope, he said.
Asked if the Met's tactics were wrong, while those used in his former force - Merseyside where many extra officers were immediately put on the streets - were right, Mr Hogan-Howe said: "I'm not disagreeing with that.
"I don't think anything I've said today is inconsistent with that. But the great benefit, of course, that they had was that they had 24 hours' notice."
Giving evidence to MPs on the Commons Home Affairs Select Committee, Mr Hogan-Howe said the force needed to review its intelligence, resources and tactics in the wake of the riots.
"The three of those, we're now reviewing whether or not we could have done those better," he said. "I'm sure we can do those better in the future."
He added: "We need to review our tactics to make sure we are far more flexible than we appeared on those three days. It does seem to me that on the Saturday there was a riot, people were angry, and there was a response against the police and that led to serious disorder.
"Then the press carried that, those images, and on the Sunday and Monday people believed they could get away with it and continued to do it. We have to respond very rigorously at the beginning to stop it getting out of control."