Did you see the response to your previous post?
Define a summary field as the "count of" some never empty field such as your drop down controlled field where you select "intruder", "fire", etc.
Select the options I recommended earlier in this post that you made: Creating a chart from field data
And specify the summary field as the field you want to chart here.
You'll need to put this chart in the layout body and sort your records by the drop down field to group them into groups so that each group is a "wedge" in your pie chart.