Booking role-play (20 minutes prior to start time)
As people enter the space for the workshop, have two volunteer police 'question' and 'book' the participants as they come in the door.
Police should use 'bluff' and state that they will be arrested if they go inside. Police should attempt to get participant's names, IDs and searching them, etc.
This should be as realistic as possible (perhaps costumes, notebooks, etc.).