Victims of stalking have been let down by the police in the past, a senior officer said today.
Assistant Chief Constable of Greater Manchester Police Garry Shewan said forces across the country had not "been there" to help people facing such harassment.
His comments came as a survey revealed only half of stalking victims complain to the authorities.
Assistant Chief Constable Shewan, the head of stalking, harassment and honour-based crime for the Association of Chief Police Officers (Acpo), told the Tonight programme: "We know that in the past it's been hit and miss in terms of whether a victim of stalking has received great help or not so good help."
But he added: "We're determined that nationally the police service will be consistent and provide a better service.
"We haven't been there in the past and that has led to some very tragic consequences but we're determined to make a difference from now on."
A survey of 2,122 stalking victims, the biggest of its kind in the UK, found just 55 per cent said they turned to police.
Three quarters (77 per cent) of those told researchers for Network for Surviving Stalking they only reported their issue after 100 occasions or more.
Just 21 per cent of victims believed police were sufficiently aware of the needs of stalking victims, and 80 per cent felt that they should be specifically trained to better handle cases of stalking.
This year the police have launched a new risk assessment tool called DASH, which covers domestic abuse, stalking and harassment and honour-based crime.
Police investigating reports of these crimes will now use a questionnaire designed to identify high-risk factors that may indicate the situation could be escalating.
All the information is recorded and kept on file with the potential to be shared with other agencies, even if the victim decides not proceed with charges.
Assistant Chief Constable Shewan added: "Identifying risk is the key to success. No police officer ever goes out to underestimate the problem or to not take the right action.
"All police officers join to make a difference. But if you haven't understood the risk, if you haven't understood the relationship between the offender and the victim, if you haven't identified what is the difference between someone who is coping with some repetitive contact, or someone who is at real risk of serious harm and possibly serious violence, then the police officer may not take decisive action."
Of the victims who took their stalker to court, 45 per cent did so more than once, the survey found.
A sixth (15 per cent) took their stalker to court twice and 16 per cent did so three times.
One in ten had been to court four times, and the remaining 14 per cent went to court between five and 10 times. All were separate prosecutions.
Assistant Chief Constable Shewan said: "I can't again, underestimate the opportunity that exists now to identify risk better than we've ever done before."
* Cops vs Stalkers: Tonight will be broadcast tonight at 8pm on ITV1.Reuse content