In many articles on this blog I show how maps can be copied to Power Point, and additional data added. Then the maps can be copied to PhotoShop and saved as a JPG used in future blog articles. Below is an example.
If you want to use Chicago Police District boundaries as your base map, here's a link to the City of Chicago site.
Here's a link to a map showing Chicago Police Beats.
Thank you to Josh Kalov for sharing this link on a #chihacknight page.