You thought it wouldn't hurt to tell the cop your side of the story--after all, you have nothing to hide. Being at a party where someone was assaulted doesn't make you a criminal. And anyway, what were you supposed to do--step in and help? So the cops found heroin there, too. You didn't have any on you. And you got out of there before they could ask any questions.
But now they have tracked you down, and they know you were there. They've called you and asked you to come down to the station. What can it hurt? You can clear this up quickly. Besides, they would tell you if you were being investigated. Wouldn't they?
Don't do it!
Talking to a cop is possibly the worst decision you could ever make in your life. A cop is not your friend. A cop wants to solve a case. And a cop doesn't care if he takes you down while he does it. Think you're in the clear because he didn't read you your rights? Think again. If you are not under arrest, an officer has zero obligation to Mirandize you.
Think because you are at the station, he has to be straight with you? The answer is a resounding no. You made the decision to go down there--it was strictly voluntary and as far as the courts are concerned, you could have left at any time. If you chose not to, and you incriminated yourself, well, that's on you. And no one else.
Do I have any rights?
You have one simple irrefutable right: The right not to incriminate yourself. How do you do that? Keep your mouth shut. Don't answer questions, don't take a cop's call, don't go see him at the station and for, heaven's sake, do not ever allow him into your house.
Feel intimidated? Think you should at least be polite? Here is your polite response: I choose not to speak to you without my lawyer. That's it--that is the first, and only, thing you need to say. Don't ask whether this had to do with the party last week, the oxy you gave to a friend or the expired tabs on your car. Just don't. Don't accompany your statement with some salty language and choice swear words. Say it simply and matter-of-fact. And end the conversation there: Close the door, hang up the phone, walk away.
You have to protect yourself
You have rights, but it is up to you to protect them. Time and again people get caught when an officer plays "good cop" and starts what seems like a friendly conversation. Don't fall for it. Cops are trained to get you to talk, and they'll keep at it until you invoke your right to silence. Experience has shown that the most damaging testimony nearly always comes directly from the mouth of the person charged.
Learn those 10 words: I choose not to speak to you without my lawyer. Memorize them. Practice them until they roll off your tongue like last week's football scores. Protect yourself: Because if you don't, nobody else will.