Cell Tower Dumps and the Fourth Amendment

Advancements in communications technology all but guarantee that Fourth Amendment issues will continue to be the subject of intense litigation as that new technology is employed by criminals and subject to surveillance by law enforcement. From automobile black boxes and GPS devices to IP surfing surveillance, courts have weighed in on the constitutional implications of law enforcement surveillance involving advanced technologies.¹ This article will address another communications technology enhanced tool—the “cell tower dump”—and its Fourth Amendment implications, which the U.S. Supreme Court has yet to resolve.

The Cell Tower Dump

In the usual case, a cell tower dump is utilized by law enforcement to assist in the identification of cellular telephones in use near a specified location on a certain date and time. This is to be contrasted with the more routine request for cellular telephone usage otherwise known as cell site location information (CSLI) or call detail for a particular identified cellular telephone, that is, a request for dialed digits consisting of calls to and from the telephone number with the locations and sectors of the cell towers through which each call originated and terminated.² CSLI assists in determining the general locations of the cellular telephone, and aids in identifying the suspect using the phone.³ In a cell tower dump, the specified location is identified by the cell towers in the area of the location. The suspect phone is usually unknown. The cell tower dump information results in the identification through cellular service provider records of all the cellular telephones that were somewhere in the vicinity of the particular cell tower on the date and time in issue, resulting in data that may generate additional leads or evidence depending on the scope of the matter under investigation.⁴ For instance, in one high profile case, the FBI obtained cell tower dump records corresponding to the area and time of a dozen bank robberies by the so-called “Scarecrow Bandits” who had victimized banks in the Dallas area. These tower dump records reflected the cellular telephones using the cell tower closest to the banks at the time of the robberies. These extensive records showed several of the defendants’ cellular telephones which used those cell towers at or around the time of each robbery. Moreover, there were also numerous calls between other members of the robbery crew under investigation that were linked to the two main defendants, as well as to the cell tower near the banks that were robbed.⁵ The data from the cell tower dumps was crucial in bringing to justice the entire bank robbery crew. In another case, Matter of D.O. v. D.O.,⁶ police obtained a search warrant for defendant’s Facebook data based upon information received from a cell tower dump, which disclosed that defendant’s cell phone was near three burglary sites at the same date and time the burglaries occurred. The tower dump, the Facebook data and information supplied by an informant further corroborated defendant’s involvement in the burglaries.