Prado Navarette in August 2008 was driving 30 pounds of marijuana through California when he was stopped by the cops on suspicion of drunk driving. His case went all the way to the Supreme Court. And today, in a blistering dissent joined by three of the court's liberal justices — Sonia Sotomayor, Ruth Bader Ginsburg, and Elena Kagan — Justice Antonin Scalia defended Navarette, arguing that the search of his car was a violation of the Fourth Amendment's protections against unreasonable searches and seizures.

But Scalia was unable to convince his conservative confreres, who joined a majority opinion by Justice Clarence Thomas that deemed the search legal. The issue before the court was this: Whether the Fourth Amendment requires an officer who receives an anonymous tip regarding a drunken or reckless driver to corroborate dangerous driving before stopping the vehicle.

Prado Navarette fell under suspicion after a 911 caller said Navarette had run her off the road. She described Navarette's truck and even told authorities the license plate number. Police took this as suspicion of driving under the influence of alcohol, and found the truck Navarette was driving. The cops followed him for five minutes before pulling him over, at which point they discovered he was not drunk. But his car was searched anyway, and the drugs were found.

Thomas says the cops were within their rights to rely solely on the anonymous witness' observations. Scalia's dissent rips the majority opinion limb from limb.

Scalia contends that police had no reason to credit the 911 caller's story in the first place, much less believe Navarette's erratic driving was the result of mental impairment. People may make a sudden or reckless-seeming maneuver in their vehicle for all sorts of non-criminal reasons. "I fail to see how reasonable suspicion of a discrete instance of irregular or hazardous driving generates a reasonable suspicion of ongoing intoxicated driving," Scalia writes (emphasis original). Amusingly, Scalia says that this one instance of dangerous driving could have been caused by Navarette's trying to avoid a pothole, or simply being distracted by an argument about sports with his brother.

Scalia contends that Fourth Amendment jurisprudence holds that officers must suspect an ongoing crime to stop someone. But in this case, "in order to stop the petitioners the officers here not only had to assume without basis the accuracy of the anonymous accusation but also had to posit an unlikely reason (drunkenness) for the accused behavior."

He admits that the anonymous call may have been a reason to observe the car for erratic behavior, but once the cops had observed Navarette's impeccable driving for five minutes, they no longer had any reason to believe Navarette was committing a crime. In fact, this observation should have discredited any suspicion. Further, he says the majority erred by asserting that Navarette could have somehow improved his drunk-driving once he became aware of the police. He writes:

I take it as a fundamental premise of our intoxi­cated-driving laws that a driver soused enough to swerve once can be expected to swerve again — and soon. If he does not, and if the only evidence of his first episode of irregular driving is a mere inference from an uncorroborated, vague, and nameless tip, then the Fourth Amend­ment requires that he be left alone. []

Scalia concludes:

After today's [majority] opinion all of us on the road, and not just drug dealers, are at risk of having our freedom of movement curtailed on suspicion of drunkenness, based upon a phone tip, true or false, of a single instance of careless driving. []

Both opinions are worth reading. I agree with Scalia that it is troubling that the court ruled today that a simple, uncorroborated phone tip can lead to a search of a person and their effects. At first blush that would seem to encourage malicious tipping. Scalia calls the majority's reasoning "a freedom-destroying cocktail."

Having said all that, while I think Scalia easily has the better of the argument in Navarette v. California, it is worth reflecting on what a credit this case is to our judicial system. In most countries on Earth, the top jurists in the nation would never question whether a single search initiated by local police was reasonable and legal, especially when it resulted in the apprehension of a man who was committing an arguably graver offense than the one of which he was suspected. Indeed, this is unusual by the standards of the rest of the world and history, and a great inheritance from the common-law tradition.

Now if only the court would adopt Scalia's high standard for other cases, including the search of persons on city streets and the collection of data by the national security apparatus.