ALBUQUERQUE (CN) — The ACLU sued Albuquerque for information on how its police use Stingray cellphone spying technology, and whether they use it for immigration enforcement, but Albuquerque claims all such records are confidential — including whether they use Stingrays at all.

International Mobile Subscriber Identity catchers — also known as cell-site catchers or Stingrays — simulate cell phone towers, pulling in all cellphone use within a certain distance. They can scan an area near targets of investigations for location and usage information, and in some cases can listen to conversations and track texts on phones in range, including those which have nothing to do with the investigation.

The ACLU of New Mexico submitted an Inspection of Public Records Act (IPRA) request on May 22, seeking records on whether Albuquerque police own any Stingray devices; what policies, if any, they have on handling data gathered by the trackers; whether the devices are used for immigration investigations; and whether police must get a warrant before using them.

The city replied on June 5 that all this information was confidential, under the law enforcement exception of the IPRA, which included “law enforcement records that reveal confidential sources, methods, information or individuals accused but not charged with a crime. Law enforcement records include evidence in any form received or compiled in connection with any criminal investigation or prosecution by any law enforcement or prosecuting agency, including inactive matters or closed investigations.”

But the ACLU says those exceptions have nothing to do with the information it requested.

Its public records request to the city is appended to its short July 6 lawsuit in Bernalillo County Court.

ACLU of New Mexico executive director Peter Simonson said in a statement: “The City of Albuquerque has a track record of using the law enforcement exception as a fig leaf when they don’t want to share public records.

“If Albuquerque is going to have the transparent and accountable police department we deserve, the city needs to stop stonewalling and disclose information about how it collects and uses cell phone data.

“These devices are incredibly invasive and the government isn’t being transparent about how they are being used. If APD is using Stingrays to snoop into people’s private information, the public has a right to know. We also need to ensure that protections are in place to prevent these powerful tools from being misused or abused.”

The Albuquerque Police Department has been under federal investigation for years, and court-appointed monitoring, for excessive force and police killings.

Police spokeswoman Celina Espinoza told the Albuquerque Journal that the department “follows legal standards with the use of any technology” but would not comment further.

Whether Fourth Amendment protections from unreasonable search and seizure apply to digital information may be addressed this fall, when the U.S. Supreme Court has hears Timothy I. Carpenter v. United States, a question of whether police need a warrant to collect cellphone records relating to location.