The police must be more accountable to the public, Conservative leader David Cameron has said.
Mr Cameron also praised London Mayor Ken Livingstone's efforts to boost community policing in the capital.
He told BBC One's Politics Show there needed to be a "big cultural change" in the police and that he favoured elected police commissioners.
The Tory leader's comments follow the fatal shootings of three teenagers in south London in less than a fortnight.
In the interview broadcast on Sunday, he said he thought police felt "put upon" by Home Office regulations and targets, rather than being focused on the people they were meant to be serving.
"And that's the big cultural change that needs to take place in the police," he said.
"The police are supposed to be accountable to police authorities, but I don't think anybody knows who sits on police authorities or what they do.
"And so we've said why not replace the police authorities with a single elected police commissioner, not a police chief - he or she wouldn't run the police - but they would be the chief focus for public accountability."
The Metropolitan Police have stepped up operations in the south of the capital following a spate of shootings.
But Mr Cameron said the reason there was more beat-based policing in London as a whole was because the city has an elected mayor.
And he said this was a situation he would like to see repeated across the country.
'Waste of money'
The Conservative leader renewed his strong opposition to identity cards and the building of "fingerprinting centres" to gather data for them.
"I think this is going to be a gigantic waste of money. I think this is going to be Labour's plastic poll tax," he said.
"Even the elderly and infirm who have never done anything wrong in their entire lives are going to have to travel up to 60 miles to these fingerprinting centres.
"This is the government that can't deliver a child support agency properly to find thousands of absent parents. They can't make the rural payments agency work to pay tens of thousands of farmers.
"And yet they expect us to believe they can have a national database for 60million people. Frankly it's beyond belief."
Mr Cameron said he would "pull the plug" on identity cards and spend more money on prisons and drug rehabilitation instead.
He also said he would continue to focus heavily on green policies.
"The environment is not just an important issue, but actually, securing a good and green environment is as important as the strong society and strong economy that we believe in."
Mr Cameron admitted he had "made mistakes", after revelations he had smoked cannabis when he was a teenager at Eton, but said he was "very comfortable" leading the Conservatives.
"I think I've got the right judgements, I've got the abilities to do the job," he said.
"I'm human, I've made mistakes, I will make more mistakes and it's for people to judge me as a person, as a politician, as a character, as a leader and, in the end, they'll make the judgements and I just have to do my best."
Mr Cameron said he had not dwelt too much on the last week.
"If you spend your whole time looking back and thinking, 'Well, how did that go and how did this go?', you'd never have any time to look forward," he said.