New Jersey Appellate Court Sets Constitutional Limits on Tower Dump Warrants

Earlier this month an appellate court in New Jersey issued an opinion in State v. Bryant, holding that tower dumps are Fourth Amendment searches that require particularized warrants supported by probable cause. 

This ruling is the latest in decisions scrutinizing the constitutionality of tower dumps. 

What Are Tower Dumps and Why Do They Matter?

Cell site location information (CSLI) is created whenever a cell phone connects with a cell tower, creating a digital trail of devices that are linked to specific towers at specific times. While CSLI has made headlines in cases where the information has been used to reveal a single person’s location over an extended period of time, tower dumps cast an even wider net by requesting information on all devices connected to a particular cell site. 

The Bryant Decision: Drawing the Constitutional Line

In Bryant, the state sought warrants for subscriber information on all phones connected to cell towers within a 193.66-mile radius over an hour and 45 minutes. This request ultimately swept up data on 10,477 users. The warrants also asked for extensive personal details, including names, billing addresses, Social Security numbers, and dates of birth.

The court’s message was clear: “[T]ower dump searches can be constitutional, but they need a warrant, and the warrant must be particularized and supported by probable cause.” The Bryant warrants failed on both counts. The court found the warrants overbroad as there was no probable cause to believe that thousands of individual cell phone users were involved in a crime committed by two perpetrators and a co-conspirator. The warrants’ geographic area was also deemed overbroad when the state requested data from all cell sites providing service to or “in close proximity to” the crime scene. Finally, the court found the warrants lacked particularity because they authorized the government to obtain more subscriber information than was necessary. Thus, the warrants’ broad geographic scope and the volume of subscriber information violated both the Fourth Amendment and the New Jersey Constitution.

Smith and Spurlock on Reverse Warrants

The Bryant decision aligns with a growing body of federal case law demanding tighter controls and greater specificity in law enforcement’s use of reverse warrants. In United States v. Smith, the U.S. Court of Appeals for the Fifth Circuit held that geofence warrants, which require technology companies to identify all users present in a geographic area during a specific time, are inherently unconstitutional under the Fourth Amendment. The court reasoned that these warrants operate in reverse, searching for suspects among the general public without individualized suspicion, and are therefore modern-day general warrants. The court concluded that geofence warrants are categorically prohibited by the Fourth Amendment, though it declined to suppress evidence in that case due to law enforcement’s good-faith reliance on existing legal standards at the time.

Building on Smith, the U.S. District Court for the District of Nevada in United States v. Spurlock found that tower dump warrants are “materially indistinguishable” from geofence warrants and are likewise general warrants forbidden by the Fourth Amendment. The court noted that tower dumps collect location data on all devices connected to a cell tower during a specified period and held that such warrants are unconstitutional. However, as in Smith, the court declined to suppress the evidence due to the novelty of the investigative technique and the absence of binding precedent at the time.

Why This Matters

The Bryant, Smith, and Spurlock decisions reflect how some courts are increasingly skeptical of permitting broad, indiscriminate data sweeps that capture the private information of thousands of innocent individuals. Instead, they are demanding targeted, justified searches supported by probable cause and particularity.