I'm hoping someone can give me a few pointers on how real-life police would handle the following scenario:
It is nighttime. two men are observed having a bit of an altercation, during which one draws his handgun and aims it at the other man. Someone calls the police, who turn up just as the second person removes himself from the scene and the first person is reholstering his weapon, which has not been fired.
He has a permit to carry a concealed weapon, and all his other papers are in order. He is believed to be associated with A Certain Federal Agency, but carries no ID from them. For the purpose of the exercise you may assume he's under extremely deep cover and cannot carry ID, nor would the Agency in question own up to him if they were contacted. For his part, he will neither confirm nor deny his association with that Agency.
My question is, having found him thus, would the police detain him? "Invite" him down to the local precinct for some questioning? Assuming they do, would they handcuff him? What sort of treatment might he receive from them in connection with the incident? What type of relevant tests, forensic or otherwise, would they want to carry out before they let him go?
FWIW, the guy with the gun is the "good guy", and the one without is the "bad guy". The police never see or speak to the bad guy during this scenario.
I have already written this scene, but there's just a niggling doubt that I might have got the finer details a bit wrong, and I'd like a few suggestions of how it should go.
the setting is modern day "generic north america", as in it's never specifically stated that the characters are in any one town or any one state, but rather left as fairly generic as possible.
I've researched the question through various means, including using the various "howdunnit" books on police procedures, and googling on such terms as "concealed weapons", "police procedure" and the like.
thanks for any suggestions.