Miranda as a Rule of Evidence
One common misunderstanding of Miranda — which Scott’s comment displays despite this having been repeatedly pointed out to him in the past — is that it found a constitutional right to be read your rights. It did no such thing, as I’ve pointed out in several other contexts. What Miranda did was create, in effect, a rule of evidence as to the circumstances under which one’s waiver of their constitutional rights would be deemed voluntary. The case was in response to a mountain of police interrogation tactics designed to deceive and coerce suspects into (knowingly or unknowingly) waiving their constitutional rights and thereby obtain confessions; these tactics themselves had evolved in response to shockingly recent restriction on physical coercion of confessions. The Court recognized — properly — that a confession obtained through these new tactics of trickery and psychological intimidation was little more voluntary than a confession obtained through physical violence. I think implicit in the Court’s decision in Miranda is also a recognition that it would be impossible to ban every single coercive tactic that could be used in interrogation — every time a tactic was banned, the cops would just create a new one.
So, given that the goal of any interrogation is ultimately to coerce a person into waiving their Fifth Amendment rights against self-incrimination, the Court came to the somewhat logical conclusion that the cops should be damn sure that the suspect at least knowingly waives those rights. Without a knowing waiver of one’s Fifth Amendment rights (and the notion that rights — constitutional or otherwise — must be on some level knowingly waived has a fairly long history in our jurisprudence), then it’s not exactly a huge leap of logic to conclude that a confession obtained under circumstances explicitly designed to be coercive was, in fact, coerced against one’s will in violation of their right against self-incrimination.
So the question the Court decided was not “is there a constitutional right to be read your rights?” but rather “under what circumstances will we permit a conclusion that a defendant has knowingly waived his rights?” So Miranda did not create an independent, constitutional right to be read your rights — for example, you cannot sue under Section 1983 for a deprivation of your constitutional rights merely because you are interrogated without being Mirandized or give a confession without being Mirandized. Instead, it simply found that if the cops are going to coerce you into waiving your rights, then at a minimum they should make sure you know what those rights are.
What the study cited in my post shows, and what the statistics on in-custody confessions post-Miranda likewise show, is that this minimum set of standards has little practical effect other than to sanctify deceptive — but quite possibly necessary — interrogation tactics as a Constitutional matter. To the extent Miranda was designed to prevent false confessions or at least coercive confessions — and I’m willing to be convinced that it was not so designed — it appears to have failed.