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The Allowable use of Cell-Site Simulators

By Keith Violante

In a recent statement, the Department of Justice adopted a new policy for the use of cell-site simulators, a highly controversial cell phone surveillance tool that can be used to determine the approximate location of a cell phone.[1] When a modern cell phone is turned on, it operates by sending out signals, or “pings” to nearby cell towers, every seven seconds, on a continuous basis.[2] These signals used by the cell service provider to service the cell phone with the best reception with respect to their geographic location.[3] Cell-site simulators or ‘Stingrays” function by mimicking a cell tower to intercept the target cell phone’s signal to determine the user’s location.[4]

Under the new policy, law enforcement agencies are required to obtain a search warrant “supported by probable cause and issued pursuant to Rule 41 of the Federal Rules of Criminal Procedure” prior to the use of a cell-site simulator.[5] The new policy also recognizes two exceptions where a warrant is not required 1) exigent circumstances under the Fourth Amendment, and 2) exceptional circumstances where the law does not require a warrant.[6] In applying the exigent circumstances exemption, courts have generally considered whether an extreme threat to public safety exists. In United States v. Caraballo,[7] the court upheld the real time “pinging” of a suspects cell phone under the exigent circumstances doctrine when law enforcement had a “strong belief” that the suspect has committed an “execution style” murder earlier that day, was presently armed and dangerous and posed a serious threat to public safety if not swiftly apprehended.[8]

In applying the “exceptional circumstances” exemption, law enforcement is required to obtain “judicial authorization before use of the cell-site simulator, based on the government’s certification that the information sought is relevant to an ongoing criminal investigation.”[9] In applying this standard courts have typically considered whether the suspect had a reasonable expectation of privacy in their cell phone location information. In United States v. Barrera-Barron,[10] the court denied a defendant’s motion to suppress evidence obtained through the use of a cell-site simulator when he was not a named subscriber on the provider’s service plan. The Court found the defendant did not have a subjective expectation of privacy because the cell phone was not registered to him or his business, and no other evidence connected the cell phone to the defendant.[11]

In other cases, the court also considered whether the suspect’s location could be tracked using any other means. In United States v. Skinner,[12] the Sixth Circuit held that the government did not violate a defendant’s Fourth Amendment rights by using a cell-site simulator to track a suspected drug dealer while he was traveling on public thoroughfares because “that same information could have been obtained through visual surveillance.”[13] Alternatively, In United States v. White,[14] found that that law enforcement’s use of a cell-site simulator to search a suspects cell phone location information was prohibited by the Fourth Amendment. The court found that the government’s warrant lacked sufficient probable cause to authorize the ongoing surveillance of the suspect’s cell phone location information lasting thirty days based on the assumption that such information would tie the suspect’s illegal activity to a particular place.[15]

In conclusion, it is clear that the recent change in the Department of Justice’s policy regarding the appropriate use of cell-site simulators will draw a bright line in many cases. However, it could also be argued that the policy permits a number of exceptions where a warrant would not be required. Accordingly, the Department of Justice will need to continue to ensure any developments will conform to the Department’s philosophy.

[1] Department of Justice, Department of Justice Policy Guidance: Use of Cell Site Simulator Technology, 1 (Sept. 10, 2015),

[2] State v. Earls, 70 A.3d 630, 632 (N.J. 2013).

[3] William Curtiss, Triggering A Closer Review: Direct Acquisition of Cell Site Location Tracking Information and the Argument for Consistency Across Statutory Regimes, 45 Colum. J.L. & Soc. Probs. 139, 143 (2011).

[4] Id.

[5] Supra Note 1, at 3.

[6] Id. 3-4.

[7] United States. v. Caraballo, 963 F. Supp. 2d 341 (D. Vt. 2013)

[8] Id. at 346.

[9] Id. at 4.

[10] United States v. Barrera-Barron, 2013 WL 3989182 (D. Kan. 2013)

[11] Id. at 6.

[12] United States v. Skinner, 690 F.3d 772(6th Cir. 2012)

[13] Id. at 778 (citing United States v. Knotts, 460 U.S. 276, 281 (1983)).

[14] United States v. White, 62 F. Supp. 3d 614 (E.D. Mich. 2014).

[15] Id. at 624 (noting that long-term prospective tracking may be justifiable in cases where there is a serious threat to public safety (i.e. domestic terrorism)).


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