Investigators must obtain a search warrant from a judge in order to obtain cellphone tower tracking data that is widely used as evidence to show suspects were in the vicinity of a crime, a federal appeals court ruled Wednesday.
A three-judge panel of the 11th U.S. Circuit Court of Appeals determined people have an expectation of privacy in their movements and that the cell tower data was part of that. As such, obtaining the records without a search warrant is a violation of the Fourth Amendment's ban on unreasonable searches and seizures, the judges ruled.
"While committing a crime is certainly not within a legitimate expectation of privacy, if the cell site location data could place him near those scenes, it could place him near any other scene," the judges wrote. "There is a reasonable privacy interest in being near the home of a lover, or a dispensary of medication, or a place of worship, or a house of ill repute."
The ruling does not block investigators from obtaining the records — which show which calls are routed through specific towers — but simply requires a higher legal showing of probable cause to obtain a search warrant rather than a less-strict court order.