Almost everyone owns a cellphone, but that doesn't give police a free pass to search for them, the federal appeals court in Washington, D.C., ruled Friday.

In its opinion, the court said the fact that most people carry cellphones “was not enough” to justify a warrant allowing police to search a suspect's home in hopes of finding one. The court vacated Ezra Griffith's conviction for illegally possessing a firearm on the grounds that the illegal gun police found in his girlfriend's home should have been suppressed at trial due to an invalid warrant. The court ruled for Griffith 2-1, with Judge Janice Rogers Brown dissenting.

“We are aware of no case, and the government identifies none, in which police obtained authorization to search a suspect's home for a cellphone without any particularized information that he owned one,” wrote Judge Sri Srinivasan.

A spokesman said the U.S. Attorney's Office is reviewing the opinion and has no comment at this time. Kirkland & Ellis partner William Burgess and associate Matthew Downer represented Griffith pro bono, in conjunction with the Federal Public Defender's office.

Police obtained the warrant to search Griffith's girlfriend's home, where he lived at the time, while investigating a homicide in which he was suspected of driving the getaway car. In the supporting affidavit, a veteran detective said gang members involved in criminal activity typically use cellphones to communicate with one another, based on his experience.

A magistrate judge issued the warrant, allowing police to search the home for all cellphones and other electronic devices. When police arrived, but before they entered, an officer saw Griffith throw a gun out the window. Police seized the gun, and Griffith was convicted of illegal possession of a firearm.

The court said the affidavit “provided virtually no reason to suspect that Griffith in fact owned a cell phone, let alone that any phone belonging to him and containing incriminating information would be found in the residence.” Applications for search warrants, the court said, must show cause to believe evidence will be found at the place to be searched, and that there is a link between the items police plan to seize and the criminal behavior at issue.

“Finding the existence of probable cause in this case … would verge on authorizing a search of a person's home almost anytime there is probable cause to suspect her of a crime,” the opinion said. “We cannot accept that proposition.”

The government argued that even if the warrant were invalid, the evidence could still be included at trial because the police who searched the home acted in good faith. Brown agreed with this argument in her dissent, writing the majority opinion “misconstrues the very purpose of the exclusionary rule.” The rule allows evidence to be excluded at trial if it was obtained via unlawful means.

“Nothing in the record suggests the officers involved in this case were doing anything other than attempting to solve an unsolved murder while scrupulously observing the letter of the law,” Brown wrote. “Yet, today's opinion impugns their motives by declaring their reliance upon a search warrant approved by a disinterested magistrate to be 'entirely unreasonable.'”

The government also argued Griffith gave up his right to suppress the firearm because he threw it out a window. The court rejected that argument too, pointing out he only did so “in response to the police's announcement that they had a warrant to search the apartment.”

“Because the warrant was invalid and the officers thus lacked authority to execute the announced search, we find suppression of the firearm to be warranted,” the decision said.

David Sklansky, former federal prosecutor and criminal law professor at Stanford Law School, said the decision is part of a “broader phenomenon” in which courts are “struggling” to apply the Fourth Amendment in cases dealing with cellphones, computers and other devices in the internet age.

He said the opinion essentially equates the warrant at issue to a “general warrant,” a British practice that gave the government power to conduct sweeping, broad searches. It was this type of warrant that the framers of the Constitution sought to avoid with the Fourth Amendment, Sklansky explained.

“In this case the court was dealing with an investigative tactic that on its face looks like you could use it to search not only the cell phone of any person … but their home, including any parts of their home that could contain a cell phone. That seems very close to a kind of general warrant,” Sklansky said. “I think that, like lots of judges, the D.C. Circuit panel has that in their back of their mind and that's part of what's motivating this decision.”

In her dissent, Brown wrote the majority's decision was the first time the court refused to apply the good-faith exception due to an overbroad warrant. She admonished the court for casting aside the officer's experience in its critique of the affidavit, and said there was “no doubt” the case would be used to “further undermine the good faith exception.”