Justice Thomas's partial dissent in yesterday's school near-strip-search case contains this paragraph:
The majority's decision in this regard also departs from another basic principle of the Fourth Amendment: that law enforcement officials can enforce with the same vigor all rules and regulations irrespective of the perceived importance of any of those rules. "In a long line of cases, we have said that when an officer has probable cause to believe a person committed even a minor crime in his presence, the balancing of private and public interests is not in doubt. The arrest is constitutionally reasonable." Virginia v. Moore, 553 U. S. ___, ___ (2008) (slip op., at 6). The Fourth Amendment rule for searches is the same: Police officers are entitled to search regardless of the perceived triviality of the underlying law. As we have explained, requiring police to make "sensitive, case-by-case determinations of government need," Atwater v. Lago Vista, 532 U. S. 318, 347 (2001), for a particular prohibition before conducting a search would "place police in an almost impossible spot," id., at 350.
I often like much of Justice Thomas's work, but here it seems that he errs.
The notion that judges shouldn't evaluate the supposed severity of various crimes in applying constitutional tests is plausible. In fact, as I discuss in Crime Severity and Constitutional Line-Drawing, 90 Va. L. Rev. 1957 (2004), the Court has indeed sometimes endorsed this notion, including in the Fourth Amendment area. In Mincey v. Arizona (1978), for instance, the Court declined to create a "murder scene" exception to the Fourth Amendment warrant requirement, reasoning that courts had no manageable standards for drawing a line between murders and other crimes:
[T]he public interest in the investigation of other serious crimes is comparable. If the warrantless search of a homicide scene is reasonable, why not the warrantless search of the scene of a rape, a robbery, or a burglary? "No consideration relevant to the Fourth Amendment suggests any point of rational limitation" of such a doctrine.
Likewise, in New Jersey v. T.L.O. (1985), the Court allowed searches of public school students based merely on reasonable suspicion, and refused to limit such a doctrine to searches for evidence of serious offenses:
We are unwilling to adopt a standard under which the legality of a search is dependent upon a judge's evaluation of the relative importance of various school rules .... The promulgation of a rule forbidding specified conduct presumably reflects a judgment on the part of school officials that such conduct is destructive of school order or of a proper educational environment. Absent any suggestion that the rule violates some substantive constitutional guarantee, the courts should, as a general matter, defer to that judgment and refrain from attempting to distinguish between rules that are important to the preservation of order in the schools and rules that are not.
But other cases have disagreed. Tennessee v. Garner (1983) held that the Fourth Amendment generally bars the police from shooting at a fleeing felon unless "the suspect threatens the officer with a weapon or there is probable cause to believe that he has committed a crime involving the infliction or threatened infliction of serious physical harm." Though "burglary is a serious crime," the Court concluded, "it is [not] so dangerous as automatically to justify the use of deadly force," because it is "a 'property' rather than a 'violent' crime."
Likewise, in Welsh v. Wisconsin (1984), the Court held that a warrantless home arrest couldn't be justified by the Fourth Amendment's exigent circumstances exception when the person was being arrested for a nonjailable misdemeanor. The misdemeanor was drunk driving, which at least one member of the majority thought was very dangerous. Still, the Court concluded that Wisconsin's classification of the misdemeanor as a nonjailable offense was "the best indication of the State's interest in precipitating an arrest, and is one that can be easily identified both by the courts and by officers faced with a decision to arrest."
And the Court's Fourth Amendment "special needs" cases (more or less the ones where the usual probable cause requirement is relaxed, as it is in schools) at times stress the harmfulness of the conduct that the search or seizure is trying to uncover. See, e.g., Mich. Dep't of State Police v. Sitz (1990) (stressing, in upholding checkpoints aimed at catching and deterring drunk drivers, "the magnitude of the drunken driving problem" and "the States' interest in eradicating it"); Skinner v. Ry. Labor Executives' Ass'n (stressing the "compelling Government interests served by" a drug and alcohol testing program for railway employees involved in certain train accidents). It's not clear, though, how significant a role this factor plays, or when the Court would conclude that the need is not great enough. In Delaware v. Prouse (1979), for instance, the Court suggested that checkpoints might be permitted even to check to make sure people aren't driving without a license or a registration. Conversely, in City of Indianapolis v. Edmond (2000), and Ferguson v. City of Charleston (2001), the Court struck down drug checkpoints and the testing of obstetrics patients for drugs, because these programs were aimed at advancing "the general interest in crime control," even though the crime that they were trying to control was quite serious, likely as serious as drunk driving. The Court's special needs cases today thus seem focused primarily on whether the searches and seizures are aimed at some interest other than uncovering crimes (as opposed to trying to catch a specific criminal), on how intrusive they are, and on how much discretion they leave to the police. Nonetheless, while the seriousness of the crime being detected or deterred seems to be less significant, some still valid precedents do rely on the premise that certain searches are justified precisely by the seriousness of the crime involved.
To be sure, requiring government officials to make case-by-case evaluations of crime severity based on the specific facts of each case might well make the rule too unpredictable (though, in a related area, case-by-case evaluations of probable cause based on the specific facts of each case are precisely what Fourth Amendment law often requires). But some sort of evaluation based at least on the type of crime involved is indeed required by Tennessee v. Garner. And more broadly, even if the caselaw generally avoids case-by-case evaluations (one item that the quote from Justice Thomas's opinion condemns), it does not uniformly apply to enforcement of "all rules and regulations irrespective of the perceived importance of any of those rules."
So it seems to me that Justice Thomas's opinion here finds consistency and uniformity in an area where the cases are either inconsistent with each other or at least not uniform (even if their positions can be somehow reconciled). Perhaps the position that Justice Thomas is endorsing with regard to crime severity and constitutional line-drawing is the sound one. But it seems to me that it needs to be defended more on the merits, rather than by reliance on a supposedly "basic principle" derived from the existing precedents — precedents that are actually quite mixed on this question.