I tell my students all the time:
1. If cops show up to your house and there is no visible criminal behavior, DO NOT LET THEM IN.
2. If you are arrested, say nothing other than “I want a lawyer,” until he shows up.
3. Always remember that the police are the prosecution’s professional witness in your court case - be very polite to them, follow their directions, but know your rights.
Given the asymmetry on making false-statements (i.e. the police can lie to you, but you cannot to them) what prevents them from pretending to be, or hiring someone to act like, your lawyer in order to violate the attorney/client relationship?
If they are able, willing, and unprosecuted for planting false evidence then why should we assume that anything they do would be morally (or lawfully) right?