If you were going to simulate an evidence search, the authorities these days like to withhold information in case of media leaks. Instead of telling the SAR people to look for a gun or a knife or a body part...they'll just tell everybody to start looking or something generic like just 'a weapon' or 'clothing'. You could do the same then leave multiple 'weapons' (or whatever) in the area and see how they deal with each one...or if they ignore something important because it's not obviously a weapon (like a bat or a tire iron or something).