Facts and legal background to the case are easily explained. Supreme Court case law on the Fourth Amendment's warrant requirement holds that "the consent of one who possesses common authority over premises or effects is valid as against the absent, nonconsenting person with whom that authority is shared" (established in US v. Matlock, 415 U.S. 164 (1974). The Randolph case raised the question of whether this rule applied to the situation where the "nonconsenting person" (Scott Randolph, in this case) was not "absent" but at the door when the police came, actively objecting against a search for which his estranged wife (Janet Randolph) had given permission.
Several of the Opinions filed provide interesting discussions of the respective roles standards and rules should play in this area of the law. This is an issue that keeps returning to the Court. Only last term, the Justices were divided along rules/standards lines where dog searches for drugs were concerned ( in USSC Illinois v. Caballes (2005) - here on FindLaw - not discussed in the Opinions in Randolph). Now, the issue is consent of a co-tennant
Justice Souter's Opinion for the Court begins with a reference to "the Fourth Amendment rule ordinarily prohibiting the warrantless entry of a person's house as unreasonable per se", to which searches "with the voluntary consent of an individual possessing authority" for a "jealously and carefully drawn exception". From a methodological point of view, this reads as: (1) an overall balancing-based framework, an (2) exception cast in form of a rule, and (3) an exception to this exception, which is said to be "jealously and carefully drawn", but of which the methodological form is not immediately clear. Ultimately, the form of this second exception will prove to be the defining issue for the case and the main point of contention between Majority and the Dissent of Chief Justice Roberts.
Back to the Court's decision. Justice Souter's Opinion goes on to find that "the constant element in assessing Fourth Amendment reasonableness in the consent cases [...] is the great significance given to widely shared social expectations". Based on these expectations, "shared tenancy is understood to include an 'assumption of risk', on which police officers are entitled to rely", that a co-habitatant may give consent to a search of common spaces. However, this "social practice" has no application to the situation in which the objecting co-tenant is actually present. In such a case, "in the balancing of competing individual and governmental interests entailed by the bar to unreasonable searches, the cooperative occupant's invitation adds nothing to the government's side to counter the force of an objecting individual's claim to security against the government's intrusion into his dwelling place". As is written further on, "Disputed permission is thus no match for this central value of the Fourth Amendment, and the State's other countervailing claims do not add up to outweigh it".
Justice Souter recognizes that this reasoning leaves several "loose ends", the most important of which is the question as to the continued significance of the Court's earlier 'consent-decisions', such as Matlock. In some of these earlier cases, the (later) defendant was asleep in the appartment or in a car not far away. "If those cases are not to be undercut by today's holding", the Opinion says, "we have to admit that we are drawing a fine line: if [the potential defendant] is in fact at the door and objects, the co-tenant's permission does not suffice for a reasonable search, whereas the potential objector nearby but not invided to take part in the threshold colloquy, loses out. This is the line we draw, and we think the formalism is justified". Asking the police to take any additional steps would be "unjustifiably impractical". "Better to accept the formalism of distinguishing" the earlier cases concerning nearby-but-not-present-potential-objectors than to impose such time-consuming requirements without apparent "systemic justification".
A Concurring Opinion by Justice Breyer provides a fifth vote (out of eight; Justice Alito did not participate), but seems to take a very different approach (one that, according to Linda Greenhouse in the NY Times probably almost went the other way in terms of outcome; note Chief Justice Robert's reference to Justice Breyer's Opinion as joining "what becomes the majority Opinion"!). "If Fourth Amendment law forced us to choose between two bright-line rules, (1) a rule that always found one tentant's consent sufficient to justify a search without a warrant, and (2) a rule that never did, I believe we should choose the first. (...) But the Fourth Amendment does not insist upon bright-line rules. Rather, it recognizes that no single set of legal rules can ever capture the ever changing complexity of human life. It consequently uses the terms 'unreasonable searches and seizures'. And this court has continuously emphasized that 'reasonableness...is measured...by examining the toality of the circumstances". For Justice Breyer's, this "totality of the circumstances" is critical, and he signals that he finds that the circumstances of the case "do not suffice to justify abandoning the Fourth Amendment's traditional hostility to police entry into a home without a warrant".
For the Dissenters, the fact that the Majority's rule is "so random in its application" (eg. no protection for defendants asleep or at work in the garden) "confirms that it bears no real relation to the privacy protected by the Fourth Amendment". "We should not embrace a rule at the outset that its sponsors appreciate will result in drawing fine, formalistic lines", the Dissenters find. Their proposed rule (no balancing here!) would hold that a co-habitant's consent should suffice for police searches, "acknowledging that shared living space entails a limited yielding of privacy to others, and that the law historically permits those to whom we have yielded our privacy to in turn cooperate with the government".
It is difficult to appreciate precisely the relevance of these invocations of 'rules' and 'standards' and 'formalism'. On the one hand, it would clearly be an illusion to think that 'hard cases' - as this one arguably is, especially given the state of precedent - can be solved through strict adherence to methodological preferences; much more is obviously at stake, here as in other cases. On the other hand, the fact that a theme such as 'formalism' is explicitly and extensively discussed among Majority and Dissenters, would appear to show that the Justices feel there are battles to be fought (and won) on this point. This, in turn, would indicate the danger of underestimating the influence of methodology. What seems certain, though, is that the Fourth Amendment - applied daily by scores of police officers around the country - will continue to provide an engaging setting for such battles.