An interesting case is coming up before the Supreme Court. The famous Miranda warning, et al., is derived from the Fifth Amendment right against self-incrimination. Given the coercive nature of the state, of being in police custody (just look at any pre-Miranda crime TV or movie for examples), it’s been an extremely powerful protection against police essentially beating confessions out of people.
In the case before the court, though, is the question of whether police must Mirandize suspects, or stop asking them questions when they ask for a lawyer, if they don’t plan on prosecuting them. If I’m not really interested in sending Joe Perp into the slammer, but I think he’s got the goods on Sammy Wiseguy, can I interrogate Joe in a way that would invalidate using any of the evidence so gathered against Joe, but still use that evidence on Sammy?
Note that even if the Supremes rule that this is permissable, it’s not a return to the days of rubber hoses and physical abuse (to the extent that those days are behind us). Such behavior is still illegal, especially if the police are going to turn around and cut the arrestee loose. But it could put an interesting twist in the decisions police make up front about interrogations — and for some interesting new episodes of Law & Order.