Mobile phone tracking is raising concern over constitutional rights, as federal law enforcement continues to use “stingray” technology to locate crime suspects.
The case of Daniel David Rigmaiden, set to open today in the U.S. District Court of Arizona, sheds light on the use of “stingrays,” a generic name for devices designed to locate a mobile phone even when it’s not being used to make a call. They are considered so critical to FBI investigations that the federal agency aims to keep information about their design and use under wraps.
However, Judge David Campbell will hear a request by Rigmaiden to have information about the government’s secret usage of stingrays disclosed to him in order to build a defense. Rigmaiden currently faces fraud charges.
Rigmaiden’s defense invokes the Constitution’s Fourth Amendment, which prohibits unreasonable search and seizure. Rigmaiden, who maintains his innocence, claims that stingrays used to search for devices, such as smartphones, in homes without a valid warrant is in violation of the Constitution.
The Fourth Amendment raises questions about the use of location-tracking technology in general, and Rigmaiden’s case focuses specifically on what kind of court approval is necessary to ensure the amendment’s protections.
Prosecutor Frederick A. Battista said the government obtained a “court order that satisfied the language” in the federal law on warrants, but the information provided to get the court order to use the stingray device reportedly didn’t reveal the technology, which may be standard practice.
The litigation includes argument over whether the orders used to authorize stingrays were appropriate, with the defense maintaining that it needs to know the information about the stingray’s use. The government argues that disclosure of that information would defeat the technology or make it easily detectable.
Stingrays work by mimicking a cellphone tower, getting a phone to connect to it and measuring signals from the phone. It lets the stingray operator “ping,” or send a signal to, a phone and locate it as long as it is powered on.
Stingrays can help police locate suspects and aid search-and-rescue teams in finding people lost in remote areas or buried in rubble after an accident. The devices, which vary in shape can be carried by hand or mounted in cars, are only sold to law-enforcement and government agencies.
Local law enforcement in Minnesota, Arizona, Miami and Durham, N.C., either possess the devices or have considered buying them, according to the Wall Street Journal. The sheriff’s department in Maricopa County, Ariz., reportedly uses the equipment on a monthly basis.
The information stingray-like devices reveal is useful to law enforcement, and supporters argue that information pertains only location, not the contents of conversations, which is addressed by wiretap laws and require a warrant.
To obtain a search warrant from a court, officers need to show “probable cause,” a reasonable belief based on factual evidence, that a crime was committed. Lesser standards apply to other court orders and technology like stingrays, which fall in a category of technology called “pen registers,” which gathers information from phones but not content. “Pen registers” don’t require probable cause for court orders.
But Rigmaiden’s defense argues that higher standards apply for the use of stingray technology. Some argue that stingrays’ transmission of location information requires higher standards for authorization.
Lawmakers and the courts haven’t yet settled under what circumstances locating a person or device constitutes a search requiring a warrant. And in the Rigmaiden case, the orders remain sealed, making further determinations difficult.
Rigmaiden’s legal team argues they should be given information about the device and about other aspects of the investigation that located him. How well that argument plays out before Judge Campbell’s courtroom may clarify the increasingly fragile balance between the government’s ability to pursue evidence and Fourth Amendment rights against unreasonable search and seizure.