The Supreme Court handed down a notable Fourth Amendment ruling this morning in Rodriguez v. United States, holding that the Fourth Amendment does not allow the police to extend the duration of a traffic stop without reasonable suspicion, even for just a “de minimis” amount of time, for reasons unrelated to vehicle and driver safety. The vote was 6-3, with Justice Ginsburg writing for the majority and Justices Kennedy, Thomas, and Alito dissenting. I’m pleased with the Court’s opinion. The Court’s holding, and the reasoning, matches up well with the approach I have suggested.

The issue in the case: When the police make a routine traffic stop, can the police delay the duration of the stop, even just for a small amount of time, to wait for drug sniffing dogs, absent any articulable suspicion to believe that there are drugs in the car? The Court has previously held that officers are allowed to use drug-sniffing dogs at a traffic stop so long as the use of the dogs does not delay the stop. This case raises the flip question: What if use of the dogs delays the stop just a little bit. Is that okay? How much leeway do the police have on the duration of the stop, given that a traffic stop is a seizure and its duration would normally determine how reasonable the delay is?

The case may ring a bell for regular readers, as I’ve blogged about it a bunch of times. My prior posts include this post when the lower court ruled; this post when the Court granted cert, this video after the grant, and this post after the Supreme Court’s argument.

On to the new decision. The majority opinion begins with what is the most important analytical step in the opinion: Answering the permitted constitutional “mission” of a traffic stop. According to the Court, the fundamental mission of a traffic stop is “ensuring that vehicles on the road are operated safely and responsibly.” This principle allows officers to inquire into the traffic violation that justified the stop, as well as to make other safety-related checks:

Like a Terry stop, the tolerable duration of police inquiries in the traffic-stop context is determined by the seizure’s “mission”—to address the traffic violation that warranted the stop, Caballes, 543 U. S., at 407, and attend to related safety concerns, infra, at 6–7. See also United States v. Sharpe, 470 U. S. 675, 685 (1985); Florida v. Royer, 460 U. S. 491, 500 (1983) (plurality opinion) (“The scope of the detention must be carefully tailored to its underlying justification.”). Because addressing the infraction is the purpose of the stop, it may “last no longer than is necessary to effectuate th[at] purpose.” Ibid. See also Caballes, 543 U. S., at 407. Authority for the seizure thus ends when tasks tied to the traffic infraction are—or reasonably should have been—completed. See Sharpe, 470 U. S., at 686 (in determining the reasonable duration of a stop, “it [is] appropriate to examine whether the police diligently pursued [the] investigation”).
. . .

Beyond determining whether to issue a traffic ticket, an officer’s mission includes “ordinary inquiries incident to [the traffic] stop.” Caballes, 543 U. S., at 408. Typically such inquiries involve checking the driver’s license, determining whether there are outstanding warrants against the driver, and inspecting the automobile’s registration and proof of insurance. See Delaware v. Prouse, 440 U. S. 648, 658–660 (1979). See also 4 W. LaFave, Search and Seizure §9.3(c), pp. 507–517 (5th ed. 2012). These checks serve the same objective as enforcement of the traffic code: ensuring that vehicles on the road are operated safely and responsibly. See Prouse, 440 U. S., at 658–659; LaFave, Search and Seizure §9.3(c), at 516 (A “warrant check makes it possible to determine whether the apparent traffic violator is wanted for one or more previous traffic offenses.”)

With that mission defined, the Court concludes that bringing out drug sniffing dogs are outside the mission and can’t support a delay absent reasonable suspicion:

A dog sniff, by contrast, is a measure aimed at “detect[ing] evidence of ordinary criminal wrongdoing.” Indianapolis v. Edmond, 531 U. S. 32, 40–41 (2000). See also Florida v. Jardines, 569 U. S. 1, ___–___ (2013) (slip op., at 7–8). Candidly, the Government acknowledged at oral argument that a dog sniff, unlike the routine measures just mentioned, is not an ordinary incident of a traffic stop. See Tr. of Oral Arg. 33. Lacking the same close connection to roadway safety as the ordinary inquiries, a dog sniff is not fairly characterized as part of the officer’s traffic mission.

Then the question becomes, is there a reason to allow a “de minimis” extension of the stop for reasons outside the mission of the stop? No, the Court reasons: The permitted length of the stop is defined by how long it takes to diligently complete the steps that are part of the core mission of the stop.

Finally, the Court rejects the government’s argument that it should be the overall reasonableness of the duration of the stop that matters. Let’s say an officer completes a stop really quickly and then waits for the dogs. Should the delay then be allowed because the overall stop wasn’t unreasonably long, even though part of that time was waiting for the dogs? No, the Court concludes:

The Government’s argument, in effect, is that by completing all traffic-related tasks expeditiously, an officer can earn bonus time to pursue an unrelated criminal investigation. See also post, at 2–5 (THOMAS, J., dissenting) (embracing the Government’s argument). The reasonableness of a seizure, however, depends on what the police in fact do. See Knowles, 525 U. S., at 115–117. In this regard, the Government acknowledges that “an officer always has to be reasonably diligent.” Tr. of Oral Arg. 49. How could diligence be gauged other than by noting what the officer actually did and how he did it? If an officer can complete traffic-based inquiries expeditiously, then that is the amount of “time reasonably required to complete [the stop’s] mission.” Caballes, 543 U. S., at 407. As we said in Caballes and reiterate today, a traffic stop “prolonged beyond” that point is “unlawful.” Ibid. The critical question, then, is not whether the dog sniff occurs before or after the officer issues a ticket, as JUSTICE ALITO supposes, post, at 2–4, but whether conducting the sniff “prolongs”—i.e., adds time to—“the stop,” supra, at 6.

A few thoughts:

(1) It’s a correct decision, I think. I’m particularly pleased that the Court adopted the safety-based rationale for traffic stops. As I blogged before, I think that is exactly right, and there hasn’t been much authority on this. For authority, the Court mostly relies on dicta in Prouse and Wayne LaFave’s oft-cited treatise. In the grand scheme of things, that’s relatively slim doctrinal pickings. But I think the Court was quite right on this, and that it’s a conceptually important step.

(2) Similarly, it’s important that the Court distinguished Terry stops from traffic stops. There is caselaw on the proper length of Terry stops, but I read Rodriguez as saying that the proper length of traffic stops is a different animal. That’s doctrinally quite important. In Caballes and Muehler, the Court indicated that the police are allowed to look for evidence of criminal activity during traffic stops, by asking questions and bringing in the dogs, as long as they don’t extend the length of the stop. Rodriguez imposes some limits on that by adopting a more limited framework for the duration of the stop and saying that the criminal-related steps can’t extend the stop even a second beyond that.

Of course, as with every defense win in Fourth Amendment law, some will criticize the opinion for not going far enough. But Caballes made time the key variable, and given the arguments in play, Rodriguez ends up imposing a limit on the variable of time.

(3) The most important sentence in the opinion is this: “Authority for the seizure thus ends when tasks tied to the traffic infraction are— or reasonably should have been —completed.” Unpacking that, there are two limits on the duration of a traffic stop. First, the stop has to end When the safety-related tasks are done (absent reasonable suspicion that turns the traffic stop into a Terry stop). Second, the stop has to end when the safety-related tasks should have been done (again, absent reasonable suspicion that turns the traffic stop into a Terry stop). Either limit is sufficient.

This means that there are two kinds of Rodriguez claims defense counsel can make. First, they can argue that the tasks actually had been completed and the stop was over, not allowing any further delay. Second, they can argue that the officer was taking his sweet time and delayed the stop, ending his constitutional authority for the stop even though the safety-related checks were not complete. (The latter kind of claim is probably more important, even though the former is the focus of Rodriguez.)

Justice Thomas points out a possible implication in his dissent:

The majority’s rule . . . imposes a oneway ratchet for constitutional protection linked to the characteristics of the individual officer conducting the stop: If a driver is stopped by a particularly efficient officer, then he will be entitled to be released from the traffic stop after a shorter period of time than a driver stopped by a less efficient officer. Similarly, if a driver is stopped by an officer with access to technology that can shorten a records check, then he will be entitled to be released from the stop after a shorter period of time than an individual stopped by an officer without access to such technology. . .

Under its reasoning, a traffic stop made by a rookie could be executed in a reasonable manner, whereas the same traffic stop made by a knowledgeable, veteran officer in precisely the same circumstances might not, if in fact his knowledge and experience made him capable of completing the stop faster.

That may be right, although it depends in part on how you measure how much time is “reasonable” to complete “tasks tied to the traffic infraction.” This raises the classic question of how you measure reasonableness: Is a reasonable time period for a particular stop measured in the abstract, independent of the characteristics of the individual officer, or is it measured for a particular officer with particular experience and access to specific technology? How much do you take into account the officer’s specific training, experience, and speed?

(4) Rodriguez is more important for its impact on police asking questions than use of drug-sniffing dogs. Drug-sniffing dogs are brought around on occasion, but officers ask questions outside the scope of the traffic stop all the time. (An aside: Is the remedy for the second kind of Rodriguez violation — that is, a claim that a stop went on for too long because the officer was dilly-dallying — suppression of evidence from the entire stop, or only suppression of what occurred after the stop should have ended? I would think the latter. If that’s right, the officer’s incentive is to ask incriminating questions, request consent, etc., early on in the stop to avoid getting close to the line. At the end of the stop, when the officer is handing back the driver’s license and maybe writing a ticket or a warning, the officer still can ask questions unrelated to the stop. But at that point officer is going to be vulnerable to a Rodriguez challenge that the officer improperly delayed the stop to ask unrelated questions.)

(5) Justice Thomas’s dissent begins with some plausible points, although I think he hits some off notes in Part II.C. starting at the bottom of Page 7. There, Justice Thomas criticizes the majority for missing the fundamental distinction between probable cause and reasonable suspicion. If I understand Justice Thomas correctly, he is arguing that because Terry allows all sorts of things based on reasonable suspicion, then it must be that the law should allow more when the government has probable cause.

But I think it’s Justice Thomas who is missing the fundamental distinction, between crimes and civil offenses. Terry stops are only allowed when there is reasonable suspicion of a crime. In contrast, traffic stops are allowed when there is probable cause even of just a civil traffic violation. That’s a notable difference. The powers an officer has to investigate civil traffic violations are less than the powers an officer has to investigate criminal activity. For example, an officer can arrest someone based on probable cause to believe that he committed a crime, but the officer doesn’t have powers to arrest someone based on probable cause that he committed a civil traffic offense. As I’ve blogged before, it doesn’t work to speak of “probable cause” or “reasonable suspicion” in the abstract. The issue is always, “probable cause of what?”

Looking at Nebraska’s traffic offense caselaw, there appears to be some uncertainty about whether basic traffic offenses count as civil or criminal for Fourth Amendment purposes. See State v. Knoles, 199 Neb. 211 (Neb. 1977). I haven’t looked closely enough at the Nebraska statutory scheme to be sure one way or the other. But if Nebraska’s traffic violations are only civil violations, then that explains the different treatment. On the other hand, if Nebraska’s traffic violations are criminal offenses, then that raises a different possible argument the state could have raised — but didn’t — to justify the stop. That is, the state could have invoked Terry to justify the detention instead of the Whren/Prouse traffic violation line of cases.

Post-Rodriguez, I think it remains uncertain whether the allowed duration of a traffic stop for a violation in a traffic-violations-are-crimes jurisdiction is any different from the allowed duration of a traffic stop for a violation in a traffic-violations-are-civil-offenses jurisdiction. Maybe criminalization of the traffic code gives the police more time, in exchange for added protections to the defendant such as the proof-beyond-a-reasonable-doubt standard. We’ll see what lower courts do with that. But that was an issue not raised in Rodriguez, which appears to have been litigated on the assumption that the initial stop was a routine traffic stop for a non-criminal traffic violation.