Also, when a cop asks you if he can enter your house, treat him like a vampire. Do not let him enter, walk outside, lock the door behind you if you have to or ask if he has a warrant. If he does not, ask him to leave. If he has a warrant, be nice, obey his instructions, but by all that is holy, shut the hell up until you talk to a lawyer.
Adding to your point. The best advice I've heard on this (I'm not a lawyer) is to ask one and only one question... may I leave? If you are not being detained I'm told that it's best to leave ASAP because the temptation to help becomes overwhelming.
Proud Life Member: National Rifle Association, California Rifle & Pistol Association, and the Second Amendment Foundation.
Annual Member: Revolutionary War Veterans Association (Project Appleseed) and the Madison Society.