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Crime Maps

Crimes happen. Law-enforcement agencies across the country are engaging the public by disseminating local crime information. The agencies do this for two reasons: (1) knowledgeable citizens can help solve crimes that might otherwise go unsolved, and (2) people should be forewarned and avoid becoming accidental victims of violent crimes.

A list of crimes can be published in many ways, but a presentation on a map is the best way to get an overall sense of crimes in a neighborhood. That’s where ZeeMaps steps in: we provide an easy way to publish a list of crimes on a map. We also provide a specialized search dialog to search for crimes within an area. In the following, we will walk-through the process of creating, publishing and searching a crime map.

Creating a new crime map is simple in ZeeMaps: click on the “Create Crime Map” link on the home page. You will get a dialog box to enter information about the map, e.g., its name, the neighborhood for which you are building the map. It is a good idea to put an “Admin password” for the map so only users with this password can make changes to the map.

I have named my map “Crimes in our neighborhood.” I’ve also given it an Admin password and set the starting location to San Francisco. Now when I hit the “Create” button, I get an empty map positioned in San Francisco.

Let’s start populating this empty map with some made-up crimes.

Add Markers to Map

To add crimes, we have two choices: (1) we can add one crime at a time, or (2) we can upload a list from a spreadsheet.
Let’s add one crime entry first. We do this by clicking on the menu item Additions on the menu bar above the map, and then selecting “Add Marker” from the resulting drop-down menu. This results in a dialog box for us to enter information about the marker.

The Add dialog has four tabs: (a) Location, (b) Information, (c) Media, and (d) Help. Use the Location tab to enter basic information about the crime, e.g., crime specifics, address and category. For the address, you can be as detailed as you want: enter a street address, cross-streets, or just the city. In case you do not want to give details of the location, you can use “Map Select a Location” to pin-point where you want to position the marker.

We fill out this form, including the Information tab and hit Submit.

Once we hit submit, we will see a marker added to the map for an Aggravated Assault crime category.

Uploading a list from a Spreadsheet

We will now add multiple markers at once, using data from a spreadsheet. We create a spreadsheet, with the columns “Name, street, city, postcode, category, case number, suspect, juvenille, date, time, and notes”. We add rows for each of our crime entry. Finally, we save the spreadsheet as a CSV file, and upload it to our map using the “Additions->Upload CSV” menu item. We added four entries using this method and the resulting map is shown below.

Geocoding for Crime Location

ZeeMaps will find the best fit for a location based on the information that you supply in the spreadsheet. In case you want to override the location found by ZeeMaps, or do not wish to use the geocoding provided by ZeeMaps, you can also use latitude and longitude columns to specify your own latitude and longitude values.

Searching the Crime Map

Notice the “Search” button on the published map above. (We published the map using the “Print or Share->Publish” menu item.) You can click on the Search button to search for crimes marked on the map. For example, search for all “Aggravated Assault”‘s in January. The result should be the one entry in the Tenderloin area of San Francisco.

Suspicious Activity Reports

It is easy to get users to submit suspicious activity reports and have them managed on the crime reports map. Map admins can moderate the entries so that they are published when approved.

Scalability

ZeeMaps is engineered to handle large datasets, so it can scale easily from a few entries to tens of thousands of entries. The scalability relates to both the performance of marker display as well as reducing visual clutter.

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