London's crime map was launched in September 2008
Residents of England and Wales can now access online maps which plot recorded crime in their neighbourhood.
The government pledged the maps would be available on every police force's website by the end of 2008.
The maps show where and when crime happened and they are updated on a monthly basis.
Ministers believe the maps will keep the public informed, but the Police Federation warn they may "feed local criminal intelligence".
A Home Office spokeswoman said 42 of the 43 police forces were now displaying the online map, with Wiltshire Police suffering technical difficulties.
Home Office Minister Vernon Coaker is due to visit Nottingham on Tuesday to hear how the maps are working there.
"Every single police force in England and Wales now has crime mapping," he said. "This gives comprehensive knowledge about crime patterns and hotspots to communities.
"By empowering people with this information they are able to engage more with their neighbourhood policing teams. I am sure this will lead to an even more responsive and effective police, thoroughly in tune with people's needs."
But the Police Federation of England and Wales, which represents rank-and-file officers, is concerned the maps may lead to crime hotspots.
Vice chairman Simon Reed said: "Whilst not wishing to restrict what the public can and cannot know, our concern is that statistics released on a monthly basis may feed local criminal intelligence, leading to crime hotspots, and further exacerbate the public's fear of crime.
"It is essential any information is fully explained to the public in order to avoid the negative impact of the perception of crime in their area."
Since the start of July 2008, all police websites in England and Wales have been publishing monthly crime statistics.
Online maps took the rollout of local crime information to the next level, and were part of the Policing Green Paper reforms announced by Home Secretary Jacqui Smith in July.
West Midlands and West Yorkshire police were among the first to trial the maps, which compare statistics with other areas and chart trends.