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.”