OAKLAND, Calif.—Defense attorney Martha Boersch has strong words for federal law enforcement's warrantless use of cell-site simulators, better known as stingrays.

Her client, Purvis Ellis, charged with attempted murder and racketeering, was tracked down to an East Oakland apartment in January 2013 with the help of not just one stingray, but two. Prosecutors initially insisted that only one stingray was used, but as was revealed last summer, that turned out to not be the case. The Oakland Police Department's own stingray was seemingly insufficient, so officers then called in the FBI, both times without a warrant.

"When they then take that technology and use it in a run-of-the-mill criminal case and use it secretly and clearly without providing defendants with notice or any of the Constitutional protections that a defendant is supposed to have, that's a real problem," Boersch, who herself served as a federal prosecutor for 12 years, told Ars during a recent in-person interview at her downtown office.

"Why courts are letting the government get away with it, I don't quite understand."

The stingray question is proving to be a constant thorn in the prosecution's side—the defense has seized on it as an avenue to challenge the government's case. Earlier this week, Boersch filed three new motions that an Oakland federal judge will hear next month. Her client may finally get a judicial ruling as to whether the Oakland Police Department and the FBI's stingray use here was appropriate and what effect that should have, if any, on his case.

Boersch noted that she didn’t have a problem with law enforcement using stingrays per se, but she wanted agents to be "up front about it."

"To me, the biggest issue is transparency," she continued. "Any system that is not transparent is inherently corrupt, and that's what happens when law enforcement is able to use something like the stingray secretly."

Wheels of justice

As Ars has reported for years, stingrays determine a phone’s location by spoofing a cell tower. In some cases, they can also 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. In 2015, the Department of Homeland Security and the Department of Justice, which oversees the FBI, said that they would have new policies regarding a warrant.

On January 21, 2013, Ellis was arrested not long after he was located via stingray in Apartment #112, one of many in a complex of units at 1759 Seminary Avenue in East Oakland. Several hours earlier, during the evening before, an undercover Oakland police officer was shot inside the gated parking area in front of the building. (That officer, Eric Karsseboom, accused one of Ellis’ co-defendants, Damien McDaniel, of being the one who pulled the trigger. McDaniel recently pleaded guilty—three defendants remain, including Ellis.)

In the Ellis case, prosecutors have said that no warrant was needed under the exigent circumstances exception. The defense has challenged that assertion, but the judge has not made a ruling.

Of Boersch's May 1 motions, the first was a new motion to suppress all the evidence that was found as a result of the stingray, and it applies to all three remaining defendants. In addition, she filed a second motion to suppress the evidence found in the four apartments that were searched, including #112, where Ellis was located, on account of an allegedly defective warrant.

Finally, she filed a third motion to sever Ellis' case from the other two co-defendants. She notes that her client can no longer wait for the case to unfold at the glacial pace that it has. Under the US Constitution, Ellis has a right to a speedy trial, and he has been kept in "administrative segregation," also known as solitary confinement, inside Oakland’s Glenn Dyer jail for more than two years. Until now, Ellis has waived his right to a speedy trial, but he has seemingly grown frustrated with the pace of his case.

“The application does not inform the judge... ”

The new stingray motion makes a forceful argument that deployment of a cell-site simulator requires a warrant and that warrantless searches are presumed to be unreasonable. The Oakland Police Department did file a pen register order with Metro PCS, the mobile phone carrier. That legal order, however, makes no mention of any stingray use.

In ideal circumstances, detectives typically go to a local judge before they deploy a stingray. Instead of a warrant, most law enforcement officers file an application for a "pen register and trap and trace order." Unlike the threshold for a warrant—probable cause of an actual crime—the pen register and trap and trace order only requires authorities to show "relevancy to a criminal investigation."

As Boersch writes:

The order did not allow the FBI or OPD to bypass the carriers and independently use a roaming cell-site simulator, which, as discussed above, performs very different and more intrusive functions than these. In fact, the affidavit in support of the order did not mention cell-site simulators at all or seek authorization to conduct any of the sort of electronic surveillance that the Stingrays were apparently performing. Third, if the government intended this order to cover its use of the two Stingrays, it deliberately misled the state court judge by failing to inform him of the technology being used, the materials to be collected, or the nature of the surveillance it was conducting. The affidavit in support of the order fails to mention that the FBI or OPD would be using a Stingray, cell-site simulator, or any other similar device. The application does not inform the judge that law enforcement will be using devices wholly independent of the carriers to whom the order was directed. And the affidavit fails to inform the judge that the FBI and OPD would be monitoring everyone's phone within range. If the government contends that the order authorized the use of the Stingray, then the agent's statements were necessarily deliberately misleading.

The new filings come at a time when the city of Oakland itself is thinking in entirely new ways about how best to balance the needs of law enforcement with the citizenry's right to privacy, which is enshrined in the state constitution.

On Tuesday, May 9, the Public Safety Committee is expected to formally recommend that the City Council adopt a new proposed law—believed to be one of the most stringent local surveillance oversight laws in the nation. Brian Hofer, the chair of the city's Privacy Advisory Commission, made the case for the new law in a recent op-ed in a local newspaper, the East Bay Express.

In it, he writes:

The ordinance will also shift the balance of power. By requiring Council approval for acquisition or use of surveillance technology, law enforcement will no longer be able to make secret, unilateral decisions, such as OPD's move to acquire and use a Stingray cell-phone tracking device in 2007. Our City Council found out about this in 2014, after a TV station broke the news. There was no Stingray use policy until the Privacy Commission brought one forth in January 2017.

US District Judge Phyllis Hamilton is set to hear all three motions on June 14, 2017 in federal court in Oakland.