Maryland could appeal to supreme court to reverse ruling that found police use of device to track cellphones without warrant in violation of fourth amendment

A major Maryland court ruling that found police cannot use cellphones as a “real-time tracking device” without a warrant could call into question hundreds, if not thousands, of convictions in Baltimore – and set a precedent for similar privacy cases across the US.

The ruling by Maryland’s second-highest court was the first by an appeals court to hold that using cell site simulator technology known as Stingray without a warrant violates an individual’s fourth amendment protections against illegal search and seizure.

The state has 16 days to appeal against the ruling to the state’s highest court, and legal observers expect it could reach the US supreme court. The attorney general’s office would not say whether it would ask the high court to reverse the ruling, saying it was still evaluating the case.

The technology, which is produced by the Harris corporation and is widely used by law enforcement and the IRS, imitates a cell tower, forces a phone to send a signal and traps metadata from phones that can reveal their location. A USA Today investigation has shown that the technology has been used in making arrests for everything from kidnapping to petty theft, but its use has often been obscured in police reports using vague language.

In the Maryland court of special appeals case, Kerron Andrews was wanted on attempted murder charges. When the police could not locate him, a detective got his cell number from a confidential informant and asked a judge for a “PEN register” or “trap and trace order”, a kind of court order which is not a warrant and doesn’t face the same legal requirements regarding probable cause. The information he obtained from that allowed the detective to find the general area of Andrews’ phone. Using the Hailstorm, also known generally by the name Stingray, the department was able to go to that area and pinpoint the precise location of the phone inside a specific residence, which was not his own. They secured Andrews in the location and only then obtained a search warrant.

At first, the department failed to reveal how it arrived at his location. But Andrews told his public defender, Deborah Levi, that his phone was acting funny. “It was Kerron who suspected that they had used it from the beginning because his phone was going a little crazy,” Levi said.

“When I told my lawyer, she automatically said, ‘They came to this address? This was not your address. How did they know you were there?’ So she instantly started to put in motions to find out,” Andrews told the Guardian. “She was right on it.”

When prosecutors finally disclosed that the department used Hailstorm to locate Andrews and only later obtained a warrant, Levi moved to suppress any evidence gained from the use of Hailstorm as a fourth amendment issue.

“I felt violated,” Andrews, who was released on bail on Friday, said. “I’m just thankful that it came out. Because a lot of people are sitting in jail right now that don’t even know that this was used in their case. They’re away from their families. Mine’s the first of its kind. It’s still not over yet, but it’s just betrayal.”

An ACLU report shows that 61 agencies in 23 states and the District of Columbia have purchased Stingray devices, but Levi said that this is one of the first times that the full scope of this technology has made it into the public record of a courtroom – partly because of non-disclosure agreements between the Harris corporation, the FBI and local jurisdictions. In 2011, Baltimore signed such an agreement that prevents the police department or state’s attorney’s office from even acknowledging use of the technology.

“It’s shocking,” Levi said. “They engage in a third-party contract to violate people’s constitutional rights.”

In another case last summer, when a detective refused to reveal details about the use of a Stingray device, which had located a suspect’s cellphone, as a result of the non-disclosure agreement, Judge Barry Williams said: “You don’t have a non-disclosure agreement with the court,” and threatened him with contempt.

“The non-disclosure agreement amounts to obstruction of justice and not just in one case. It amounts to systemic obstruction of justice from the state’s attorney’s office,” said Josh Insley, the defense attorney in that case.

But TJ Smith, a spokesman for the Baltimore police department, said the department’s policy has shifted: “We discuss the usage of this equipment openly in court.”

The Baltimore office of the public defender is reviewing cases it could challenge on the heels of this ruling and is focusing on the most serious 200, where people have been imprisoned because of discoveries made as a result of the undisclosed use of Stingray or Hailstorm. “And that’s just our office,” Levi said, noting that the process of dealing with all of the cases will be complicated, because Maryland law allows prisoners only one year to challenge their conviction without relying on a special post-conviction remedy, such as that recently granted to Adnan Syed, after the podcast Serial brought new evidence to light.

“This has now definitely been placed on the police and state’s attorney’s office to go back and identify people who have been wrongly imprisoned,” Insley said.

The state’s attorney’s office did not respond to requests for comment by press time.

In its ruling on the Andrews case, the court of special appeals noted that “such an extensive prohibition on the disclosure of information to the court … prevents the court from exercising its fundamental duties under the constitution”.

The use of Hailstorm and Stingray devices, Levi argued, is different than other cases using cellphone data to determine where a person was at the time of a crime because, in Stingray cases, the device “operated by emitting a signal ‘through the wall of a house’ and ‘into the phone’” thus violating a reasonable expectation of privacy.

“It’s all about the reasonable expectation of privacy and just because you have a fancy piece of equipment that no one can see, smell or touch doesn’t mean you get to use it,” Levi said.

The court agreed with her arguments, allowing that “cell site simulators, such as Hailstorm, can locate and track the movements of a cellphone and its user across both public and private spaces. Unchecked, the use of this technology would allow the government to discover the private and personal habits of every user.” The court agreed with earlier rulings that “[t]he fiction that the vast majority of the American population consents to warrantless government access to the records of a significant share of their movements by choosing to carry a cellphone must be rejected”.

Nevertheless, in part because of the non-disclosure agreements, this is the first time there has been a ruling by an appeals court on a Stingray case.

“There has been no written decision on this issue,” Levi said. “And it’s widespread all across the country and we’re hoping that people put the stop on this warrantless search.”