When you consider the scoundrels the FBI chases down every year — terrorists and serial killers and badass drug kingpins — David Rigmaiden has to be one of the dullest on the list. He's currently in federal custody in Arizona, charged in a long-running scam that netted millions from bogus tax returns.

Still, the Rigmaiden case is being watched closely because of a tool the FBI used to catch him. The device, called a StingRay, would seem right at home in any spy flick.

Suitcase-sized and portable, StingRays are used by law enforcement to track mobile phones in real time. The device electronically impersonates a cellphone tower and dupes the mobile phone into connecting through its own antennae.

Documents obtained by L.A. Weekly through the Freedom of Information Act show that the Los Angeles Police Department is quietly using the StingRay. (Police in Miami, Fort Worth and Gilbert, Ariz., also are known to have the devices.)

LAPD refuses to discuss how it uses the powerful tool, perhaps copying the FBI's playbook, which argued in the Rigmaiden case that revealing too many details would cause serious harm to future investigations.

The department, through a spokesperson, refused to comment on the device, despite repeated requests from the Weekly. Through the department's Discovery Unit, which handles requests from the public and media under the California Public Records Act, LAPD also declined to reveal any information on how the devices are used.

LAPD even refuses to say whether its detectives are required by police chief Charlie Beck and the Los Angeles Police Commission — all of whom are appointed by Mayor Antonio Villaraigosa — to obtain a search warrant before the StingRay is deployed against unsuspecting L.A. residents' cellphones.

The FBI has argued that a search warrant is not required, a question at issue in the Rigmaiden case, and one that Beck's people refused to address.

But LAPD is using the devices.

Documents obtained from the Inspector General's office of the Department of Homeland Security reveal that LAPD bought two so-called “IMSI catchers” around 2006. At the time, LAPD had “recently purchased a cellphone tracking system (CPTS) for regional, terrorist-related investigations.” The records mention StingRay and KingFish, brand names for IMSI devices made by Florida's Harris Corp.

Separate documents show that, in April 2010, the Los Angeles City Council approved the purchase of $347,050 in additional “StingRay II” equipment — and paid for it with outside funds from the Los Angeles Police Foundation, a nonprofit group that supports police functions, over which the city has no control.

Peter Bibring of the ACLU of Southern California says LAPD's refusal to discuss its internal guidelines for allowing use of the spy device is unreasonable. (Policies typically are not protected from open-government disclosure laws.)

LAPD's reflexive secrecy means, he says, “We can't have a public debate on what kinds of location-monitoring technologies are appropriate, and when they're justified.”

Bibring calls LAPD's negative reaction to the Weekly's requests “just inconsistent with the democratic process.”

The StingRay is a unique new tool, allowing police to track cellphones directly. According to Chris Soghoian, graduate fellow at the Center for Applied Cybersecurity Research at Indiana University, the StingRay exploits the architecture of cellphone networks.

Mobile devices connect to the wider network by using the antennae closest to them at the time. But when LAPD fires up a StingRay, it's often the most powerful signal in the area. Instantly, the department's spy equipment becomes the go-to “tower” for every cellphone and mobile device nearby — not just the phone carried by the suspect they're tracking.

“If the government shows up in your neighborhood, essentially every phone in the neighborhood is going to check in with the government,” Soghoian warns. “It's almost like Marco Polo — the government tower says 'Marco,' and every cellphone in the area says 'Polo.' ”

And, as in the swimming-pool game, police can narrow down the location of the phone, in this case by using triangulation.

In Arizona, the FBI obtained a court order to track Rigmaiden's laptop but didn't secure a full search warrant. Rigmaiden argues that the technology is so invasive that the government should have to meet the legal standard for getting a warrant. ACLU agrees.

But Rigmaiden, who is representing himself in court, has declined to discuss his case.

StingRays can be used by police instantly, without permission from a middleman provider such as Sprint or Nextel. Officers tailing a suspect can use a StingRay to home in on the target's cellphone, even if they aren't sure of his real name or identity.

Lee Tien, of the Electronic Frontier Foundation, sums up the problem of police acting alone — without search warrants, and without having to approach the commercial provider — saying, “Self-help always has a danger of abuse.”

If police gather information from innocent people's cellphones while casting their net, Soghoian says, “There's no icon that shows up on your cellphone that says, 'government tower.' ”

Service providers such as T-Mobile or AT&T usually require court oversight. But in situations where there isn't enough evidence to satisfy a judge, police may be tempted to simply deploy a StingRay.

Says Soghoian: “The only thing stopping the government from using this technology to listen to phone calls or spy on hundreds of innocent people are the legal policies put in place by the law enforcement agency, and the kind of court order they've obtained.”

But Beck and his spokespeople refuse to reveal to the Weekly their StingRay legal policy — and even rebuffed a simple records request, filed by the Weekly on Aug. 1, asking how much money LAPD has spent on the devices. Moreover, that was the Weekly's second request. LAPD ignored state law, taking 92 days instead of the maximum 24 allowed to respond.

Terry Francke, executive director of Californians Aware, which fights California governmental bodies reticent to open public records to public inspection, says in an email, “The public records act appears to have been grossly violated here” by Beck's staff.

Documents from the StingRay II purchase approved by the City Council in 2010 offer some insight into other reasons why Beck says he wants them. According to a memo signed by the LAPD chief, they can be used for “locating critical missing and kidnapped victims, and also assist detectives in the expeditious arrest of wanted suspects.”

Beck further claimed that the technology “has saved numerous lives.”

No Los Angeles elected official contacted for this story would comment on the StingRay technology being used within the city they represent.

A spokesman for City Councilman Paul Koretz said he wasn't familiar enough with the issue to weigh in — a sentiment echoed by press staff for City Councilman Bernard Parks (former LAPD chief of police) and City Councilman Paul Krekorian — who sits on the influential Public Safety Committee, which helps determine LAPD budgets and key law enforcement policies.

Two other members of the Public Safety Committee — council members Jan Perry and Dennis Zine, a former police officer — did not return messages left with their staff. Nor did Councilman Richard Alarcon.

Officials working under City Attorney Carmen Trutanich directed the Weekly's calls back to the police department.

Richard Tefank, executive director of the Los Angeles Police Commission, a group of powerful political appointees who delve into major issues such as police wrongdoing and have a say in many of the department's most important policies, said specific policies — such as those governing the use of StingRay in L.A. — are the responsibility of LAPD, not the commission.

The fundamental question of how much data is retained by police is another that LAPD declined to address.

As things stand, no Los Angeles resident — except those targeted by police and then prosecuted using StingRay evidence — will ever know if LAPD has rerouted their cellphone data through its system, potentially archiving their personal information along the way.

Because the StingRay usually grabs the signal of any phone nearby, good guys and bad guys alike could end up as unwitting subscribers to “LAPD Mobile.”

On the bright side, they don't require a contract.

Reach the writer at [email protected].

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