But youre told, "whatever you say can be used against you". If youre arrested, read your Miranda rights, are being interrogated, but one of the officers tells you "youre not in trouble" and you confess.. that's definitely deceptive, but does it constitute an involuntary confession?
Police use all sorts of deceptive tactics. Theyre allowed to lie about the amount of evidence they have to garner a confession. If they can lie about being in a lot of trouble, why couldnt they lie about not being in trouble?