As for police : I think they have to have the target what ever it is in site before they shoot but if the target was concealed by smoke they might not be so quick to fire on the target .What ever it is .
I'm looking for something more permanent than a soda bottle . Has anyone seen this done before . With a smoke screen it's hard to fallow someone closely down a winding road wink . So one is able to pull ahead let people out and set up an ambush .

If we are to remain free, all good men should join their local militia and learn to fight tyranny on every level and by any means necessary.
If you live in Ohio and would like to participate in Militia training contact the OVC
Ohio Volunteer Corps