Officer Placement

The officer placement program uses the data exported from the forecasting program. The purpose of this program is to best place officers where they would be most efficient at finding and effectively handling crime. An algorithm will place officers in areas of highest predicted crime so as to try to prevent it from happening, or preparing for where it is most likely to happen.

The officer placement algorithm first takes in all of the data from the data file containing the forecast data. This file contains the total crime weight in all of the recorded addresses. The user inputs a resolution value, based on how large of an area crime rate should be calculated for. This creates a system where crime predictions are put in a grid, rather than in individual points and allows for less close range of officers. This resolution should take the officer's patrolling range into account; they are able to move as opposed to standing still.

The resolution is given in meters. The program then converts meters to degrees latitude and longitude (dividing by 102,470). The latitude and longitude values of each address are multiplied by the reciprocal of the resolution, shown below.

The decimal is then removed from this number, so that areas that were within the same resolution distance would all be grouped together. Removing the decimal off of the new latitudes and longitudes allows for less accurate measurements, which will all be in the resolution distance. In the same resolution, nearby areas accumulate the total weight, as opposed to points in the same place all accumulating very different weights.

The program then finds the sum of all of the crime weights in the predicted file in the city (referred to hereinafter as the total weight). Then, it divides the total weight by the number of officers to be placed (hereinafter referenced as weight per officer) to determine how much weight, if all of the weights were in the same place, an officer would be expected to take on.

Then, each place is iterated through, and the officers are placed based on what the weight of a particular area is. For example, if an area had a weight of 50, and the weight per officer was 20, 2 officers would be placed in that area. However, the extra 10 weight was not included, so some officers will be left unplaced. After all of the places have had officers divided up amongst them, some places will have had less weight than the weight per officer, so they would not have any officers. The officers will be placed in the remaining places with no officers based on a raking system of high crime expectancy.

It should be noted that there is a parameter for the maximum number of officers in an area. An area can get up to this many officers, but cannot exceed this number. This way, there is a better distribution of officers, and an excessive number will not be placed in one area. The default maximum number of officers in an area possible is 10, but that value can be lowered by the user.