A federal appeals court ruled against a criminal defendant who challenged the warrantless use of a stingray that was used to locate him.

The Wednesday decision marks the first time that questions regarding the proper use of stingrays, also known as cell-site simulators, have reached the federal appellate level.

In the United States v. Patrick, suspect Damian Patrick had an outstanding warrant for a probation violation and was found via the use of a stingray in Milwaukee in 2013.

Stingrays determine a phone’s location by spoofing a cell tower. In some cases, they can intercept calls and text messages. Once deployed, the devices intercept data from a target phone along with information from other phones within the vicinity.

In recent years, the use of stingrays has come under increased public scrutiny. Last year, the Department of Homeland Security and the Department of Justice, which oversees the FBI, said that they would have new policies requiring a warrant.

But, as the 7th US Circuit Court of Appeals ruled on Wednesday, the fact that law enforcement didn’t have a warrant to use the stingray against Patrick is immaterial.

As the court concluded:

A person wanted on probable cause (and an arrest warrant) who is taken into custody in a public place, where he had no legitimate expectation of privacy, cannot complain about how the police learned his location. … Probable cause to arrest Patrick predated the effort to locate him. From his perspective, it is all the same whether a paid informant, a jilted lover, police with binoculars, a bartender, a member of a rival gang, a spy trailing his car after it left his driveway, the phone company’s cell towers, or a device pretending to be a cell tower, provided location information. A fugitive cannot be picky about how he is run to ground. So it would be inappropriate to use the exclusionary rule, even if the police should have told the judge that they planned to use a cell-site simulator to execute the location warrant.

Deus ex machina

As Ars reported previously, the case dates back to October 2013, when Damian Patrick was sitting in the passenger seat of a rented white Chevy Malibu parked behind a house in northern Milwaukee. Unbeknownst to him, he was being watched not only by several local police officers but by the FBI as well.

According to a police report, two Milwaukee Police Department (MPD) officers blocked the Chevy with their own car and conducted a traffic stop. The officers ordered Patrick and the driver of the car, Terrell Newman, to show their hands. The uniformed cops then opened the car and ordered the two men out. As Patrick exited the car, Officer Thomas Multhauf noticed a semi-automatic Smith & Wesson on the floor where Patrick was sitting.

The officers checked their records and found that Patrick had an outstanding arrest warrant for violating his probation. He was promptly taken into custody.

How did the Milwaukee Police Department and the FBI magically descend upon Patrick’s location? The arrest reports are vague, making references only to an "unknown source" and "prior knowledge." The report says, "We [police] obtained information" to the fact that Patrick, wanted on a felony probation violation, happened to be in that parking spot.

As the case moved forward, defense attorneys tried to challenge what they argued was an unlawful seizure of Patrick’s gun. Eventually, Patrick conditionally pleaded guilty to the single count but reserved the right to appeal.

Questions abound

In a lengthy dissent, Circuit Chief Judge Diane Wood lambasted secrecy surrounding the device.

“We know very little about the device, thanks mostly to the government’s refusal to divulge any information about it,” she wrote. “Until recently, the government has gone so far as to dismiss cases and withdraw evidence rather than reveal that the technology was used.”

As she concluded:

It is time for the stingray to come out of the shadows, so that its use can be subject to the same kind of scrutiny as other mechanisms, such as thermal imaging devices, GPS trackers, pen registers, beepers, and the like. Its capabilities go far beyond any of those, and cases such as Riley indicate that the Supreme Court might take a dim view of indiscriminate use of something that can read texts and emails, listen to conversations, and perhaps intercept other application data housed not just on the target’s phone, but also on those of countless innocent third parties.

Patrick’s attorney, Chris Donovan, did not immediately respond to Ars’ request for comment. Donovan could request that a full panel (en banc) of the 7th Circuit re-hear the case, or he could appeal up to the Supreme Court.