Today, a federal district judge in Arizona issued a very disappointing decision concerning the government’s obligations to be candid with courts about new technologies they are seeking a warrant to use.

The case involves Daniel Rigmaiden, who is being criminally prosecuted for an alleged electronic tax fraud scheme. The government used a surveillance device known as a stingray to locate Mr. Rigmaiden. A stingray operates by simulating a cell tower and tricking all wireless devices on the same network in the immediate vicinity to communicate with it, as though it were the carrier’s cell tower. In order to locate a suspect, a stingray scoops up information not only of the suspect, but all third parties on the same network in the area. This means that when the government uses a stingray to conduct a search, it is searching not only the suspect, but also tens or hundreds of third parties who have nothing to do with the matter. When the FBI sought court permission to use the device to locate Mr. Rigmaiden, it didn’t explain the full reach of stingrays to the court.

The ACLU and the Electronic Frontier Foundation filed an amicus brief arguing that when the government wants to use invasive surveillance technology, it has an obligation to explain to the court basic information about the technology, such as its impact on innocent third parties. This is necessary to ensure that courts can perform their constitutional function of ensuring that the search does not violate the Fourth Amendment. Unfortunately, today’s decision trivializes the intrusive nature of electronic searches and potentially opens the door to troubling government misuse of new technology.

In today’s decision denying the motion to suppress, the judge held that information about how the stingray operates – such as the fact that it scoops up third party data – was merely a “detail of execution which need not be specified.” We respectfully but strongly disagree.

If the government has probable cause to believe a suspect lives at a particular address and wants a search warrant, it obviously needs to tell the court if the address is a 100-unit apartment building and that the government intends to search all 100 units until it finds the suspect. Omitting such information would never be considered a “detail of execution.” Law enforcement should be held to the same standard when they conduct electronic surveillance.

The judge dismissed the significance of the stingray’s impact on third parties because the government deleted and did not review the third-party data after it located Mr. Rigmaiden. But the Fourth Amendment does not include a “no harm, no foul” rule. The violation arises from the fact that the government searched people who are not suspected of any wrongdoing. This is a violation even if the government doesn’t later use the information against those third parties.

Finally, the judge held that, under the “good faith” doctrine, suppression would not be the appropriate remedy even if there were a constitutional violation. The judge agreed with the government that the FBI agents “were using a relatively new technology, and they faced a lack of legal precedent.” Today’s ruling missed the opportunity to create an important legal precedent on electronic surveillance.

As new surveillance technology emerges, the government needs to err on the side of providing more, not less, information to magistrates. Technology evolves more rapidly than the law. Today’s decision sends the troubling message to the government that it’s alright to withhold information from courts about new technology, which means that the law will have an even harder time catching up.

(Crossposted on the ACLU of Northern California's blog)