If you are like most people, every day before you leave your home you make sure you have your wallet, keys, and cell phone. But did you know that your faithful cell phone automatically creates a log of your minute-by-minute location, with potential GPS certainty, stretching back years? Did you know that law enforcement has accessed this log to retroactively surveil people-without probable cause, and without going to a neutral judge for a warrant? That legality-or illegality-of this practice was recently addressed by the United States Supreme Court in Carpenter v. United States.


Timothy Carpenter was accused of organizing a string of robberies. Based on the accusation, law enforcement went to a number of cell phone providers, and requested the phone records for a number associated with Carpenter. Even though law enforcement lacked a search warrant, the phone companies turned over the records. The records provided included several months of cell-site records-records that indicate which cell towers a cell phone connects to while active. These cell-site records showed that Carpenter was in the vicinity of a number of the robberies. Carpenter was arrested, and while Carpenter challenged the government’s tactics, the evidence was ultimately used against him to convict him of robbery. He appealed the used of the cell-site record evidence all the way to the United States Supreme Court.

The Decision and Its Implications

In a 5-4 decision, Chief Justice Roberts held law enforcement violated Carpenter’s Fourth Amendment rights. Chief Justice Roberts acknowledged the case presented two issues: (1) whether a person has a reasonable expectation of privacy in their general movements; and (2) whether the third-party doctrine allowed disclosure of the cell-site records. Chief Justice Roberts first found that while people generally do not have a reasonable expectation of privacy in their public movements, people do reasonably expect that law enforcement will not track their every movement for years. Because the cell-site records do exactly that-provide years worth of detailed surveillance-people have a reasonable expectation in the cell-site records, and probable cause and a warrant are necessary for law enforcement to access the information.

Chief Justice Roberts also addressed the competing “third-party doctrine”-the rule that a person generally does not have a reasonable expectation of privacy in information held by a third-party. While Chief Justice Roberts did not overrule the third-party doctrine, he refused to apply it to cell-site records because requests for cell-site records are not “a garden-variety request for information from a third party” because of the “seismic shifts in digital technology that made possible the tracking of not only Carpenter’s location but also everyone else’s, not for a short period but for years and years.” Because of the “unique nature” of cell-site location information, Chief Justice Roberts concluded the third-party doctrine does not apply, and the accessing of cell-site records was a “search” requiring probable cause and a warrant in accordance with the Fourth Amendment. Essentially, Chief Justice Roberts reiterated that information provided by cell phones in the current digital age is so voluminous, ubiquitous, and essential to our day-to-day lives today that the Fourth Amendment guard against “unreasonableness” is different. In other words, Chief Justice Roberts held old rules should not be routinely applied when technological advances provide access to information unimaginable when the old rule was created.


The protections provided by the Fourth Amendment are complex and continually changing. With today’s rapidly evolving technology, it is important in every case to fully understand what technology the government can and cannot use against you. Whether the government has violated your rights depends greatly on the specific facts of your case, and it is important to have a qualified attorney review and discuss your rights. If you have a criminal issue in North Dakota or Minnesota, do not hesitate to contact the [nap_names id=”FIRM-NAME-1″] at 866-771-9930, or send an email at [email¬†protected].


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