> If the police knock on your front door and you start shredding documents, that's still a crime
Isn’t the relevant bit whether you think you’re doing crimes and/or being investigated?
If I’m shredding while the cops knock on my door because they’re looking for a missing cat, that’s obviously not criminal. (I guess the more-pertinent comparison would be they knock on my door and then I put stuff in the shredder while I check around my home.)
If you shred any evidence of a crime you are guilty of a crime regardless if the police ever knock at your door or you think you are being investigated if you have the intent "to prevent the apprehension or cause the wrongful apprehension of any person or to obstruct the prosecution or defense of any person, he knowingly destroys, alters, conceals, or disguises physical evidence or makes, devises, prepares, or plants false evidence"