The Third Circuit Court of Appeals has handed down a huge decision in favor of privacy rights in America. On Tuesday, the court confirmed in United States v. Katzin (PDF) that federal authorities must get a probable cause-driven warrant before attaching a GPS tracking device on a suspect’s car.

Of course, the circumstances of this case may sound familiar. Indeed, the Supreme Court decided in January 2012 in the United States v. Jones case that attaching a GPS device to a suspect’s car without a warrant constituted unreasonable search and seizure. In the wake of that decision, the FBI turned off 3,000 such tracking devices. However, the Jones case did not provide a clear-cut ruling on whether a lower legal standard could conceivably apply. In the new case, Katzin, the court definitively answered that with a resounding no.

As Judge Joseph Greenaway wrote:

We thus have no hesitation in holding that the police must obtain a warrant prior to attaching a GPS device on a vehicle, thereby undertaking a search that the Supreme Court has compared to “a constable's concealing himself in the target's coach in order to track its movements.”

Raiding Rite Aid

The case dates back to 2009 and 2010, when Rite Aid pharmacies in Delaware, Maryland, and New Jersey were hit with a spate of burglaries in which the bandits nearly always did the same thing before each raid: they cut the external phone line, which would sound an alarm.

By May 2010, according to the court's account, local authorities turned their attention to a local electrician named Harry Katzin as primary suspect. He had been caught burglarizing a Rite Aid, and his brothers had criminal records for burglary and theft.

Over the following months, state and federal investigators began receiving reports about Katzin’s whereabouts near various Rite Aid locations. Once, he was even caught “crouching beside some bushes outside of a Rite Aid after [the police responded] to reports of suspicious activity.” Eventually, the FBI put a “slap-on” GPS tracker on Katzin’s van with the approval of the United States Attorney, but without a formal warrant. Eventually, by mid-December 2010, Harry Katzin and his brothers, Mark and Michael Katzin, were arrested.

The defendants eventually moved to suppress evidence—allegedly stolen materials from Rite Aid—that was gathered as a result of the GPS tracking. The district court ruled in favor of that motion, which the government then appealed up to the Third Circuit.

“He acts in a constitutionally reckless fashion”

The government argued that while the search may have been warrantless and there may have been reasonable suspicion, this case did not fulfill established specific requirements that give authorities the rationale to conduct such a search.

As Judge Greenaway continued:

The Government contends that requiring a warrant prior to GPS searches would “seriously impede the government's ability to investigate drug trafficking, terrorism, and other crimes.” (Appellant Br. at 27.) We fail to see how such a conclusory assertion suffices to except GPS searches from the requirements of the Fourth Amendment's Warrant Clause. Doubtless, we are aware of the dangers posed by terrorism and comparably reprehensible criminal activity. However, we would work a great disservice by permitting the word “terrorism” (in the absence of any other information or circumstance) to act as a skeleton key to the liberties guaranteed under the Constitution.

The government also argued that it had a “good faith exception,” citing related cases in other judicial districts. Here, the court lambasted the authorities for specifically deciding not to seek a warrant.

Nothing in a law enforcement officer's duties forces him to either rely on non-binding precedent or to conduct the Fourth Amendment calculus himself by extrapolating from, or analogizing to, existing case law. Where an officer decides to take the Fourth Amendment inquiry into his own hands, rather than to seek a warrant from a neutral magistrate—particularly where the law is as far from settled as it was in this case—he acts in a constitutionally reckless fashion. Here, law enforcement personnel made a deliberate decision to forego securing a warrant before attaching a GPS device directly to a target vehicle in the absence of binding Fourth Amendment precedent authorizing such a practice. Indeed, the police embarked on a long-term surveillance project using technology that allowed them to monitor a target vehicle's movements using only a laptop, all before either this Circuit or the Supreme Court had spoken on the constitutional propriety of such an endeavor.

Both the Electronic Frontier Foundation and the American Civil Liberties Union entered as amici in the case and lauded the court’s decision.

"Today's decision is a victory for all Americans because it ensures that the police cannot use powerful tracking technology without court supervision and a good reason to believe it will turn up evidence of wrongdoing," Catherine Crump, an ACLU attorney, said in a statement. "These protections are important because where people go reveals a great deal about them, from who their friends and business associates are to what doctors they go to."

Other civil libertarians welcomed the court's ruling.

"It's awesome," Jennifer Granick, the director of civil liberties at Stanford Law School, told Ars. "On whether the Fourth Amendment applies, it follows the [Supreme Court] case of Jones, as it must. But there were all kinds of side issues which the judge correctly decided. For example, he had to decide if the Fourth Amendment meant a warrant was required for this tracking, and he said it did. There is no car exception to the warrant requirement. In short, he ensured that the Jones opinion means something in the Third Circuit."