A robbery suspect's silver Audi blew through a stop on the San Mateo Bridge Thursday, and rather than chase it, Alameda County law enforcement let a license-plate camera and a sheriff's airplane track it to four arrests near Emeryville — no pursuit, no crash, no injuries.

The Sheriff's Office is promoting the capture as proof its Real-Time Information Center keeps people safe. What the announcement leaves out is that the plate-reader network at the center of it is the same system supervisors came within one vote of rejecting seven weeks ago — after the county admitted its own surveillance data had been shared illegally with federal agencies.

The most striking thing about the four arrests Alameda County deputies made near Emeryville on Thursday is what didn't happen: no high-speed chase, no wreck, no injuries. A robbery suspect's silver Audi blew through a stop on the San Mateo Bridge, and rather than floor it after him, law enforcement let a license-plate camera and a Sheriff's Office airplane do the work. Both are arms of the county's Real-Time Information Center — and the plate-reader half of it is a program supervisors came within one vote of rejecting seven weeks ago.

The Alameda County Sheriff's Office is promoting the case as proof its Real-Time Information Center (RTIC) keeps people safe: automated plate readers locate a fleeing car, the fixed-wing plane ALCO 2 shadows it from above, and deputies close in only when a calm stop is possible. The account holds up — NBC Bay Area (external source, opens in a new tab) and KTVU (external source, opens in a new tab) both reported the tracking operation and the arrests. What the announcement doesn't mention is that this same plate-reader network was, in July, the center of an illegal data-sharing controversy that split the Board of Supervisors 3-2.

Strip away the aerial-chase drama and the mechanics are mundane, which is the point. San Mateo police tried to stop the Audi around 3:50 p.m. as it crossed into Alameda County, and when the driver wouldn't yield, they declined to pursue and handed the case to the RTIC, according to the Sheriff's Office account carried by NBC Bay Area (external source, opens in a new tab). A plate reader relocated the car near San Leandro; ALCO 2 picked it up and stayed on it as the occupants ditched the Audi for a waiting black Mercedes in Oakland. The plane fed live coordinates to deputies, who made the stop on westbound Interstate 580 near Powell Street in Emeryville. Four people were arrested.

Sheriff Yesenia Sanchez told supervisors she had responded to the leaks by cutting the number of agencies she shares data with — "shut off half the state," in her words, per Berkeleyside.

As a tactic, it is defensible — trailing a car from the air spares bystanders the danger of a ground chase. The complication is what the tactic runs on. The plate readers that found the Audi are the heart of a $2.4 million Flock Safety contract the Board of Supervisors voted 3-2 to extend on July 1 — a package of license-plate readers, pan-tilt-zoom cameras and drones, as Berkeleyside reported (external source, opens in a new tab). By that outlet's account, the vote came only after the county discovered its own surveillance data had been shared illegally with federal agencies; sheriff's staff acknowledged at the meeting that two regional intelligence "fusion centers" had pulled county plate data and passed it to out-of-state and federal agencies improperly.

ALCO 2 wasn't on that ballot. The plane belongs to the sheriff's aviation unit and is directed by that same Real-Time Information Center — the fusion hub that, by the Sheriff's own presentation to supervisors (external source, opens in a new tab), stitches plate readers, drones, fixed cameras and aircraft into a single feed. It draws from the same pool of data, and the same civil-liberties questions, as the contract supervisors nearly rejected.

Sheriff Yesenia Sanchez told supervisors she had responded to the leaks by cutting the number of agencies she shares data with — "shut off half the state," in her words, per Berkeleyside. It didn't satisfy the whole board. The two no votes came from Nikki Fortunato Bas and Elisa Márquez, the latter arguing the county lacks the safeguards such a system requires. Supervisor David Haubert, in the majority, brushed the concerns aside, saying the cameras exist to keep residents safe.

Those objections aren't abstract. The Center for Human Rights and Privacy has documented (external source, opens in a new tab) county plate-reader records reaching Immigration and Customs Enforcement and Homeland Security Investigations, and the same aviation unit that operates ALCO 2 circling peaceful demonstrations.

Thursday's arrest is the version of that system the public is meant to applaud — a suspect caught, nobody hurt. The rest of the program — data slipping to federal agents, planes over protests, a watchdog suing a neighboring city over identical practices — never makes the press release. It is all one apparatus. The question the Sheriff's Office avoids while it markets the win is who else, beyond Alameda County deputies, gets to see what the plane and the plate readers gather on the way to it.