Do Police Need a Warrant to Use a Stingray? Federal Policy, State Laws and the Courts

Short answer: federal agents under the Department of Justice and Department of Homeland Security generally need a warrant to use a Stingray-type cell-site simulator, under internal policies adopted in 2015. Several states require one by statute, and some courts have ruled warrantless use unconstitutional. But the US Supreme Court has never ruled directly on Stingrays, policies have exceptions, and local practice varies.

What a Stingray does

A cell-site simulator, often called a Stingray after a Harris Corporation product, imitates a cell tower so that nearby phones connect to it and reveal identifiers such as the IMSI, and allows investigators to locate a target phone. See our explainers on Stingray range and how to detect one.

Federal policy: warrant by default since 2015

In September 2015 the Justice Department announced a policy requiring its agencies (FBI, DEA, ATF, US Marshals) to obtain a search warrant supported by probable cause before using a cell-site simulator, with exceptions for exigent circumstances and certain "exceptional circumstances." It also required deleting data from non-target phones and barred collecting content. DHS adopted a similar policy in October 2015 covering agencies such as ICE and the Secret Service. These are policies, not statutes, and they do not bind state and local police.

State laws

A number of states have passed laws requiring a warrant or court order for cell-site simulators or real-time phone location, including California's Electronic Communications Privacy Act (CalECPA, effective 2016), Washington (2015), Utah, Illinois and others. Coverage and wording differ, so check your state's statute.

Key court rulings

• State v. Andrews (Maryland, 2016): the Court of Special Appeals held that using a cell-site simulator to locate a suspect's phone is a Fourth Amendment search requiring a warrant, and criticised a non-disclosure agreement police had signed with the FBI.
• United States v. Lambis (S.D.N.Y., 2016): a federal judge suppressed evidence from warrantless Stingray use to find an apartment.
• Carpenter v. United States (2018): the Supreme Court held that obtaining historical cell-site location records generally requires a warrant. It was not a Stingray case, but its reasoning on location privacy is widely cited in Stingray litigation.

The secrecy problem

For years many local agencies signed non-disclosure agreements with the FBI as a condition of buying the equipment, and some prosecutors reportedly dropped cases rather than reveal Stingray use in court. Records obtained by the ACLU and journalists document these NDAs and the use of vague "pen register" orders that did not tell judges what device was involved. That history is documented; how common such practices remain today is harder to verify.

Remaining gaps

• Exigency exceptions can be broad.
• Policies can change and are enforced internally.
• Many states have no specific statute.
• Use at protests and around airports raises questions not resolved by current rulings.

Our opinion: a warrant requirement that lives in an internal memo rather than federal law is a weak guarantee. Congress has seen bills such as the Cell-Site Simulator Warrant Act but none has become law as of this writing.

How to find out what your local police use

File a public records request with your city or county police for cell-site simulator purchase records, NDAs and use policies. The ACLU maintains a map of agencies known to own the devices. For federal records about yourself, see how to request your own FBI file.

Sources

• DOJ Policy Guidance on Cell-Site Simulator Technology (2015): justice.gov
• Carpenter v. United States, 585 U.S. 296 (2018): supremecourt.gov
• ACLU, Stingray tracking devices map: aclu.org
• EFF on cell-site simulators: eff.org

Frequently asked questions

Do police need a warrant to use a Stingray?

Federal DOJ and DHS agencies generally must get a warrant under 2015 policies, with exigency exceptions. Some states require one by law. There is no Supreme Court ruling directly on Stingrays.

Is Stingray use legal?

Yes, law enforcement agencies use them legally, but the legal conditions depend on the agency, state law and court rulings.

What did Carpenter v. United States decide?

That obtaining historical cell-site location records generally requires a warrant. It is often cited in arguments about Stingrays.

Can I find out if my local police own a Stingray?

You can file a public records request for purchase records and policies, and check the ACLU's map of known owners.