In a crucial legal decision in Nevada, a federal judge cast doubt on the constitutionality of a controversial investigative tool known as cell tower dumps. This law enforcement method allows police to collect data from cell phone towers at scale, capturing information on every device connected to the tower during a specific time period. The practice, which harvests location and identity information from thousands of phones, has been widely used to aid criminal investigations while also sparking heated debates about privacy and constitutional rights.
The case at the center of the ruling involves Cory Spurlock, who faces multiple serious charges, including conspiracy to traffic marijuana and alleged involvement in a murder-for-hire. In an effort to lead Spurlock to the crime scene, investigators obtained search warrants and obtained data from nearly 1,700 cellphones. The data, provided by a wireless carrier, revealed which phones were connected to specific cell towers near the alleged crime scene during the time period in question.
Crucially, none of the individuals whose data is collected explicitly consent to the sharing of their location information, and there is no mechanism for them to opt out.
After the case went to trial, Spurlock's defense team argued that the search warrant authorizing the dumping of data at the tower was too broad and effectively allowed police to track the digital whereabouts of countless innocent people. They argued that it amounted to a "general search warrant" — the kind of indiscriminate searches expressly prohibited by the framers of the Constitution.
U.S. District Judge Miranda M. Du agreed in her written opinion, ruling that the act of dumping items in a high-rise building constituted a search under the Fourth Amendment and that the search warrant failed to meet the Constitution's standards of specificity and probable cause.
Nonetheless, Judge Du eventually allowed evidence from the tower dump to be used in Spurlock's trial. She explained that the officers involved were relying on existing legal standards and that at the time of the investigation, the region's higher courts had not provided clear guidance on the use of tower dumps.
The ruling has implications far beyond the Spurlock case. Privacy advocates have long warned that cell site dumps essentially collect vast amounts of data on people not associated with criminal activity. In court, expert witnesses described how the data obtained was used to reconstruct the movements and connections of each user whose phone was connected to the targeted cell towers, raising concerns about mass surveillance and the invasion of privacy of ordinary citizens.
Nevada's ruling is similar to a similar ruling in Mississippi. Another federal judge in Mississippi ruled that “cell tower dump" is unconstitutional and prohibits its use in an FBI investigation. The case is currently on appeal, with the Justice Department arguing that it is an important tool for law enforcement and the legal issues surrounding its use remain unresolved.
The broader legal landscape is further complicated by the Supreme Court's 2018 decision in Carpenter v. United States. The ruling ruled that police generally need a search warrant to access historical cell site location data. However, the Carpenter ruling was narrow in scope and did not directly address the legality of cell site dumps or other forms of bulk data collection, leaving lower courts to consider on their own the applicability of the Fourth Amendment in these circumstances.
As legal challenges mount and conflicting rulings emerge across the country, many observers believe the Supreme Court may soon be asked to clarify the constitutionality of this approach.