Rule number one to remember when confronted by the authorities is that there is NO law requiring you to talk to the Police, the F.B.I., or a representative of any other investigative agency. Even the simplest questions may be loaded and the seemingly harmless bits of information which you volunteer may later become vital links in a chain of circumstantial evidence against you or a friend.
DO NOT INVITE THE INVESTIGATOR INTO YOUR HOME!
Such an invitation not only gives him the opportunity to look around for clues to your lifestyle, friends, reading material, etc; but also tends to prolong the conversation. And the longer the conversation, the more chance there is for a skilled Investigator to find out what he wants to know. Never open your door to an Officer. They can shove their way in. Don't open your door with the chain-lock on, either. Police are known to kick in doors. I should add, that when you let a Police Officer into your house, then he is automatically authorized to do a weapons search (supposedly for his own protection) and this can lead to all kinds of problems!
Many times a Police Officer will ask you to accompany him to the Police Station to answer a few questions. Often, the authorities simply want to photograph a person for identification purposes, a procedure which is easily accomplished by placing him in a private room with a two-way mirror, asking him a few simple questions, and then releasing him. NEVER agree to go to the Police Station. Simply say, "I have nothing to say."
If the Investigator becomes angry at your failure to cooperate and threatens you with arrest ... STAND FIRM. He can't legally place you under arrest or enter your home without a warrant signed by a Judge. (There are exceptions to this however, as in instances where he has witnessed you commit a crime, and there are times, too, where he can enter without showing a warrant up front, known as a 'no knock' entry.) However, if he indicates that he has such a warrant, ask to see it. We've heard of Cops waving a piece of paper around, claiming it was a warrant. A person under arrest or located on the premises to be searched, generally must be shown a warrant if he requests it, and must be given a chance to read it.
Without a warrant, an Officer depends solely upon your helpfulness to obtain the information he wants. So, unless you are quite sure of yourself, don't be helpful. (Note: Don't fool yourself into thinking you can talk or lie your way out of the situation. Don't be smug and think, "All Cops are stupid" and you can pull a 'fast one.' Most Police are smart individuals, they're good at what they do, and the only thing you will do is talk yourself into jail.)
Remember, talk is cheap! But when it involves law enforcement authorities, it may cost you, or someone close to you, dearly. Remember the 5 words -- "I HAVE NOTHING TO SAY." It has worked for us many, MANY times. And it will work for you!