The key to preventing child sexual exploitation is stopping young people who are "determined to put themselves at risk", from running away from care homes, the chief constable of Greater Manchester Police said.
Sir Peter Fahy insisted that the police had learned lessons after an investigation highlighted "significant failures" in the handling of widespread abuse in Rochdale.
An investigation into the force's handling of the scandal and possible misconduct by officers, led by GMP and supervised by the Independent Police Complaints Commission (IPCC), said too much emphasis was given to victims' credibility.
But it said that of the seven officers who were served misconduct notices, only one was found to have a "case to answer" and they were already retired, meaning there would be no disciplinary action.
The chief constable rejected calls from ex-detective Margaret Oliver, who has repeatedly criticised her former employers, for a full independent inquiry into the forces' actions.
"I'm not sure we need more reports because we absolutely know what the issues are," he told BBC Radio 4's Today.
"The issue is that we still haven't solved the key issue behind CSE (child sexual exploitation) which is: how do you protect vulnerable young people who are determined unfortunately to put themselves at risk, that don't understand the degree to which they are making themselves vulnerable."
Asked if he saw the problem as being children putting themselves at risk, he went on: "Yes absolutely.
"Because of their upbringing, because of their difficult situation and because they are in care, every single day we have large numbers running away.
"The public will say the obvious thing is then to put them in secure accommodation but we know that in itself causes long-term serious harm so we have to do all we can to go after the offenders and try to deal with them in different ways when we can't get the victims' evidence and try to protect victims as best we can."
In the report, GMP admitted the force was focused on tackling robbery and burglary rather than listening to the claims of young, vulnerable victims who were being sexually exploited by older men.
It concluded that the police failed to recognise the "size, gravity and extent" of the abuse and placed too much emphasis on the credibility of the victims, who had complex lives, instead of examining the crimes.
Ms Oliver, who left her job in protest at the handling of the scandal, said problems had continued beyond the period covered by the report and suggested young people remained at risk.
"I know of men who have never been arrested, who are still walking the streets of Rochdale, who victims have named and accused of abusing them," she told the programme.
She said there should be a full independent investigation of the kind carried out in to similar problems in Rotherham and suggested the officers investigated were "easy targets for the GMP media juggernaut to focus the blame on".
"It is a nationwide problem and there is still an overwhelming desire to conceal the truth. This was an opportunity, which has been missed again, to bring it all out into the open.
"Until the faults and the errors are acknowledged, I do not feel that we are ever going to move forward," she said.
Sir Peter queried her claim to have contacted him directly in 2011 about her concerns, insisting that by that stage a huge investigation was already under way.
The police had got "a lot better" at looking after victims, he said - but accused the courts of failing to make sufficient reforms to secure more convictions.
"When these young people go into the care system, their whole background, their vulnerability - they may have had a drug problem, family problems whatever - is used against them," he said.
"Although the police and social services have got a lot better at that, those issues still very much remain and so even when we do get cases to court. at the moment in Manchester there is a conviction rate of only around 50% which clearly is still very worrying."
He went on: "You can't put them under house arrest so it is about agencies working together to try to protect that person.
"But we still have a major issue that the court system struggles to deal with vulnerable victims of sexual offences where that very vulnerability - their background, the difficult background they've had - will be used against them to challenge their credibility.
"Although we have had some adjustments to the court processes and pilot schemes have been put forward, what we do need I think is a comprehensive overhaul of the way the court system deals with these sorts of cases."
Officers involved in the abuse investigation have since received "management action" in respect of their performances.