Home Map Help FAQ Trouble

Mouse over the image above for tips about the controls.

Summarize By:

You can summarize the crime counts by Police Beat, Police District, Ward, Community Area and Census Tract.

Category:

The crime data has been grouped into logical crime categories. These categories are used to display the data and provide the summary counts. For more information on the categories refer to Crime Categories.

Timeframe:

There are four choices of timeframe 90, 180, 270 and 365 days. The data is current up to the previous day. The data is dynamic and the counts shown on this site should not be considered official CPD statistics.

Legend

The Legend has four ranges denoted by four colors on the map. The ranges are determined using the nested means method. Meaning that for each crime category, timeframe and geography the ranges are calculated dynamically using the current data. This means that the ranges will change over time even when viewing the same geography, crime category and timeframe because the data is dynamic. This means the user should be careful if they try to make comparisons over time.

Statistics

The statistics provided include the total, minimum value, maximum value, the mean (average), the median (the mid-point of the data) and the standard deviation (a measure of variation away from the mean).

Records Shown

This toggle option allows the user to see only those records that are within the current MapView. For example, when viewing the data summarized by Census Tract, if the user has zoomed in to an address and has the option "Only Within MapView" selected, only those Tracts within the MapView are displayed. This makes it easier to view the counts associated with the Tracts in the current MapView instead of scrolling through the entire list of over 800 Tracts.

Summary Table

The Summary Table has three columns, the Rank, Summary Geography, and the crime category Count. Each column can be sorted ascending or descending using the arrows under the column headers. The Summary Geography (ie. Police Beat, Police District, Ward, Community Area or Census Tract) values are buttons that to allow you to zoom to that location by clicking on the link. A table will be displayed showing the crime counts over the four timeframes.

When viewing the data summarized by Census Tract clicking on the Tract number will display Census data related to that tract including population and ecomonic indicators.

Zoom To Address:

You can use either a street address or an intersection. For the best results use a complete address like 5000 W Madison St. Leaving off the street type (St) or direction (W) might cause the application to not locate the address or match an incorrect address. Sometimes new addresses might not be in the system right away, but we are constantly updating the data to insure we have the most accurate address information. For an intersection, again use the most complete information you can provide and separate the two street names using an ampersand (&). For example N Clark St & W Addison St. Do not enter any house number information when searching for and intersection. If the system can find an address match the map will zoom to that location automatically.

Zoom

There five zoom controls. The In tool allows you to click once on the map to zoom in or click-hold-drag a zoom box. The map will zoom into the location of the box when the mouse button is released. The Out tool works in the opposite manner allowing the user to zoom out on the map. The Pan tool allows the user slide around the map by clicking and holding down the mouse button and sliding a direction and then releasing the button. The map will refresh after the mouse button is released. The Back button acts like the back button on a web browser. It remembers the last location you were viewing and zooms back to that location when the button is pressed. The zoom bar allows you to zoom to a certain level by clicking on one of the boxes. The closer the box is to the In tool the closer it will zoom in on the map. The bottom box will zoom out to the entire City. The current zoom level will be indicated by the box colored red.

View

The View buttons control the display of some additional map layers . The buttons acts as toggles and repeatedly clicking the button will turn the layer on and off. The Wards button controls the ward map, the Comm. button controls the community area layer, the Tract. button controls the census tract layer, the Beat button controls the Police Beat layer. the Dist. button controls the Police District layer and the Photo button controls the display of aerial photography. The Pods button controls the display of the Police Department cameras. Pods are noted on the map by a camera icon and a pod number label. The Inset button controls the display of the inset map where the current map view is highlighted by a red square.

Email

MapLink

Clicking this button will open a new browser window with a URL link that can be emailed or shared by various electronic means. The URL encoded within the link stores the current map parameters and will open a new map window covering the exact same area with the same crime category displayed. This feature can help facilitate discussion about crime in a particular area of the City.

Print

Clicking the Map button will open a separate window with a map suitable for printing on a portrait  8.5” x 11” page. It includes the inset map and a legend. Clicking the Table button opens a separate window with the crime summary table and selected parameters. Both of these features require that any pop-up blockers be turned off.