Winnipeg Police Crimestat Maps Offer a Distorted View of Crime

There is a problem with the crime maps displayed on the Winnipeg Police Crimestat site.

If  you go on the site and draw up the map for District 1 (the downtown division) you get the following disclaimer:

Your filter selection returned 2060 incidents.  You are viewing the first 1000 crime incidents on your map window. Click on ‘view report ‘for complete crime incident details or refine your filter criteria further.

The Crimestat map for District 1, the downtown area for the period of January 1st  to November 25th 2011, displays only the first 1000 incidents reported in 2011 (Map 1).    Because the first 1000 incidents took place between January 1st  and June 24th 2011, a search for those dates will display the same map, the same 1000 incidents.

Map 1

Source: Winnipeg Police Crimestat (Retrieved on 11 11 27)

If you want to see a map that depicts the  crimes committed between June 25th and November 25th 2011, you will need to draw up a separate map. It will show the additional 1038 crimes not shown on the first map.  Map 2 displays those incidents.  Although the maps appear virtually identical, i.e. the crime pattern as largely unchanged,  subtle differences can be noted.

Map 2

Source: Winnipeg Police Crimestat (retrieved on 11 11 27)

In order to get a true view of crime in the downtown area you would need to be able to combine those two maps but the system does not allow that.

The same limitation applies when you request a map for any geographical area that has more than 1000 reported incidents.  When you draw up the city-wide map (8509 incidents reported between January 1st and November 25th 2011) the map only displays the first 1000 incidents.

Imagine what the maps would look like if you could see all incidents of reported crime!