3 ms·

Will crime maps work?

2 points by danw 18y ago

giardini 18y ago
I did a study of the utility of GIS (mapping) systems for a very large metropolitan police department years ago. My results: - GIS systems revealed nothing that officers and staff did not already know. It is difficult to impossible to know more about a location than an officer who treads the site every day. - Not a single application of GIS or mapping software was proposed that was not already done as well or better by some existing software. This despite my extensive querying of potential users, who included police staff at all levels in the department. - Mapping data was often incorrect: the officer on the beat knew that the data was wrong but most map users did not. About 20% of the data was in error. another 7% was formatted improperly and data cleanup (guessing the correct values) had to be done. - Map update was a haphazard process handled by multiple groups with little to no verification. In the end, aerial photographic proved superior to maps, although subject to the same update problems. Perhaps by flying UAV drones 24x7 police departments can maintain the views they want. - The only new application for the test systems was the use of maps for public speaking by the various chiefs of police. And citizens at those meetings were quick to point out missing or incorrect data in even those maps, leading even the chiefs to question the utility of the maps. Nobody hates being publicly pointed out for being wrong more than the chief of police. - The location of crimes is useful in allocating patrols. But that was already handled by systems that did not require a GIS/mapping system: allocation was done by beat/zipcode/street address. In the end my study was buried, several million dollars was spent on a CAD system with the justification that it would be used to do real-time tracking of probationers wearing electronic boots. The system languished for years and at last check had been retired.

3 ms·

Will crime maps work?

2 points by danw 18y ago

giardini 18y ago
I did a study of the utility of GIS (mapping) systems for a very large metropolitan police department years ago. My results: - GIS systems revealed nothing that officers and staff did not already know. It is difficult to impossible to know more about a location than an officer who treads the site every day. - Not a single application of GIS or mapping software was proposed that was not already done as well or better by some existing software. This despite my extensive querying of potential users, who included police staff at all levels in the department. - Mapping data was often incorrect: the officer on the beat knew that the data was wrong but most map users did not. About 20% of the data was in error. another 7% was formatted improperly and data cleanup (guessing the correct values) had to be done. - Map update was a haphazard process handled by multiple groups with little to no verification. In the end, aerial photographic proved superior to maps, although subject to the same update problems. Perhaps by flying UAV drones 24x7 police departments can maintain the views they want. - The only new application for the test systems was the use of maps for public speaking by the various chiefs of police. And citizens at those meetings were quick to point out missing or incorrect data in even those maps, leading even the chiefs to question the utility of the maps. Nobody hates being publicly pointed out for being wrong more than the chief of police. - The location of crimes is useful in allocating patrols. But that was already handled by systems that did not require a GIS/mapping system: allocation was done by beat/zipcode/street address. In the end my study was buried, several million dollars was spent on a CAD system with the justification that it would be used to do real-time tracking of probationers wearing electronic boots. The system languished for years and at last check had been retired.