Step 1: Enter a Seattle address to see 911 calls near that address
When you drill into a particular 911 call, look for the blue link in the tooltip to the incident report. This will take you to a Seattle Police website where once registered, you can pull up the incident report. If you get "no report available" it means no report was filed for the 911 call - this is a very normal result.
View source on this page to see the code I used to trigger the call to the Tableau viz. On the sending end, I used the google maps API to retrieve the latitude and longitude given a street address. On the receiving end inside of Tableau, we have parameters for latitude and longitude which can receive input from the URL. Finally, we have a mercator equation which allows you to specify a desired distance from your original address (download the workbook to see that calc).