If your roleplay theme can not handle a chance of cops coming your way, you should try a different approach. Cops being nosy should be nothing new to you, and being apprehended by one, whether abused or not, should be accounted for. It leaves room for police corruption.
If your roleplay partners do not have time or patience to wait 10 minutes for you to get unsuspected and back, then they wouldn't have time or patience to finish the roleplay as well, so your roleplay would be ruined either way.
If your unsuspection takes longer than 10 mins, it's your own fault and you're doing it wrong.