Your RP should depend on the situation. To take your example - in which the robber is pointing a gun to the back of your head - it would be considered bad RP if you turn around and spray him down: You wouldn't be able to pull something like this off in real life.
As for general rules, if...
Hello!
Good to see that you've been accepted for your police interview. In the PM which was sent to you by whoever accepted your application is a link to the police rules and guidelines, helping you in your interview.
The best of luck with your interview!