The Supreme Court cast doubt Monday on whether police may obtain cellphone data to find crime suspects. In a 6-3 decision, the justices said this location information showing where a cellphone user has traveled is personal and private and subject to the protection of the 4th Amendment’s ban on unreasonable searches. The court stopped short of deciding the proper basis for a search warrant in such cases, sending the case back to judges in Virginia.
How Geofence Warrants Function in Criminal Investigations
Geofence warrants represent a shift in how police utilize digital evidence. Instead of targeting a specific suspect with a warrant for a known device, investigators identify a location and time associated with a crime and ask tech companies like Google to provide data on every device that was present in that “geofenced” area. Investigators typically request a list of device IDs within a specific perimeter, such as a 150-yard radius, and then narrow that list to identify specific individuals.
The Legal Conflict Over Privacy Expectations
The central tension in these cases involves the Fourth Amendment, which protects citizens against unreasonable searches and seizures. Privacy advocates argue that geofence warrants raise the specter of mass surveillance on innocent people. Conversely, police and government lawyers argue that no one has a reasonable right to privacy when they are walking on a sidewalk or driving down the street.
Status of the Chatrie v. United States Case
The case of Chatrie v. United States originated in Virginia, where Okello Chatrie challenged his conviction for a credit union robbery. Police had obtained a geofence warrant to identify devices near the scene, which eventually led them to Chatrie. The full 4th Circuit Court of Appeals split evenly on the legality of the geofence warrant, and the Supreme Court agreed to decide the issue in Chatrie vs. U.S. In a 6-3 decision, the justices said that because an “individual has a legitimate expectation of privacy in his cellphone location data,” police investigators need a valid search warrant from a magistrate.
Key Considerations for Digital Privacy
- Data Minimization: Police have gone to Google and cellphone companies seeking tracking data on cellphones that were at a crime scene.
- Warrant Specificity: Legal experts note that the constitutionality of these warrants often depends on how narrowly the “geofence” is defined.
- Future Judicial Review: The outcome casts doubt on “geofence warrants.”