Cops’ license-plate readers keep their eye on you, Sacramento

Automated readers help find stolen vehicles—but they also record unprecedented amounts of personal data

License-plate readers are used to rescue people and stolen property, but they can also track the public’s whereabouts.

License-plate readers are used to rescue people and stolen property, but they can also track the public’s whereabouts.


As sheriff’s Sgt. Kyle Hoertsch eases his white, unmarked SUV past a diagonal bank of parked cars on Del Paso Boulevard, his onboard laptop pings like a row of winning slot machines.

A black contraption the size of a CD player points six plastic orbs through the rear passenger window, scanning one license plate after another. The device transmits alphanumeric code to a database that is recording the public’s movement on an unprecedented scale.

Ping. Ping. Ping.

In a relatively short span of years, automated license-plate readers like the one in Hoertsch’s car have gone from luxury items to must-haves for cops, thanks to the likes of Vigilant Solutions, a Livermore-based company that outfits thousands of law-enforcement agencies with its tracking technology, including every agency in Sacramento County. Vigilant’s servers hold upward of 2 billion time- and location-stamped license-plate images, and add approximately 50 million each month, it says.

In Sacramento County, the two biggest law-enforcement agencies more than tripled their number of detections between 2014 and 2015—to 37 million last year.

Cops swear by the technology and say it’s become essential to doing everything from recovering stolen vehicles to finding kidnapped children. “We’ve got numerous cases where this is used as an investigative resource,” Hoertsch told SN&R. “We use it in every aspect of the job.”

Civil-liberties advocates, meanwhile, point out that ALPRs, as they’re known, largely inventory the whereabouts of innocent motorists, information that can be easily abused in the absence of formal regulatory oversight.

“More and more cameras, longer retention periods and widespread sharing allow law-enforcement agents to assemble the individual puzzle pieces of where we have been over time into a single, high-speed-resolution image of our lives,” the American Civil Liberties Union warned in a July 2013 report on the expanding use of ALPR technology. “The knowledge that one is subject to constant monitoring can chill the exercise of our cherished rights to free speech and association.”

Or, as Berry Accius, founder of the local mentorship program Voice of the Youth, put it: “It’s like the ex-girlfriend that you know has dirty pictures of you. She may not do anything with it, but wait until you piss her off.”

But ALPRs are no laughing matter to Accius and his fellow organizers in the African-American community. To him, they sound like an extension of the surveillance authorities have historically performed on anti-establishment groups. But now they can be applied to everyone. “You may as well just stay home or take the bus,” he said.

Hoertsch says he understands the privacy concerns, but believes the upsides far outweigh the downs. And he says the sheriff’s department has imposed strict restrictions on the extent of the data dragnet and how long it can be stored.

Sheriff Scott Jones, he says, made it clear that the agency is not in the business of collecting plate numbers.

“That’s kind of the fine line,” he said.

But not all agencies are created equally.

In the city of Sacramento, the police department is collecting a lot more data and keeping it for much longer. And a nationwide shift toward what’s called “intelligence-led policing” has both the sheriff’s and police departments embracing facial-recognition software that is being deployed in public spaces without our knowledge.


Each license-plate scan captures an infrared image of the plate, a color-image of the vehicle and its GPS coordinates, and a date and time stamp, among other information. Both the sheriff’s department, which patrols the unincorporated county and city of Rancho Cordova, and the Sacramento Police Department have greatly increased their ability to collect this information, public records show.

In 2015, ALPRs employed by the sheriff’s department uploaded north of 4.9 million unique license plate reads to Vigilant’s servers, a 40 percent increase over the previous year, when 2.9 million plates were scanned.

But those figures pale in comparison to what the police department is gathering.

The sheriff’s department has a total of 20 plate-reading devices—18 mobile, mostly installed in patrol vehicles, and two fixed-location devices.

The police department, which started its program earlier, has 43 total devices, 30 of which are attached to police observation devices, or PODs, at traffic intersections throughout the city. These PODs inhale a much larger amount of data, but also make that data less exact.

For instance, in its response to an SN&R public-information request, the department said it couldn’t provide the exact number of unique license-plate reads, as the sheriff’s department had, because “the system has no automated means of differentiating the detection of a license plate from detections of other strings of characters in the everyday environment (street signs, phone numbers displayed on vehicles, etc.).”

So, with that caveat, the police department reported the total number of detections per year, which showed astounding growth in 2015. That year, the department recorded 32.1 million detections, more than four times the 7.8 million detections made in 2014.

Asked to explain the increase, police spokeswoman Officer Traci Trapani said it was due to more digital eyes going up at intersections. “The simple answer is the addition of more PODs. It’s like adding more officers on patrol,” she told SN&R. “That’s why we’re getting a lot more detections.”

Similarly, Hoertsch said a second fixed unit at an undisclosed location explains the jump in his agency’s reads. “It basically doubled the amount of scans,” he said.

The police department has already recorded 8.5 million detections through February 21 this year.

Through April 5, the PODs have recorded at least 38 stolen-vehicle hits, resulting in those vehicles being recovered and 50 individuals being arrested on theft and other charges.

“We primarily use it for stolen vehicles,” Trapani said of the program’s focus.

That’s fine, said Tessa D’Arcangelew, an ACLU of Northern California organizer who specializes in technology and personal liberties. But ALPRs and technologies like it are like huge nets that catch thousands of dolphins for every one shark. “These technologies are evolving so quickly that the laws and the best practices and the understanding of how to use them hasn’t caught up,” she told SN&R.

The PODs are mounted high and capture data other than license plates—including images of the motorists themselves through closed-circuit cameras. The department now has the equipment to do something with those headshots.

In April 2015, the Sacramento City Council authorized the police department to apply $550,000 in state grant funding to reduce vehicular thefts by purchasing more Vigilant equipment. This added 20 more cameras at intersections and installed ALPR systems in three undercover vehicles.

The contract also provided access to Vigilant’s FaceSearch software program, with a gallery of up to 50,000 images.

Police spokesman Sgt. Bryce Heinlein explained that the facial-recognition program isn’t connected to ALPRs, but is equipped to the police observation devices that are erected around the city. For instance, Heinlein said, if a POD records a suspect leaving an armed robbery, police can use facial-recognition software in an attempt to identify him.

“This system is nationwide, basically,” he said. “Our goal is to utilize it more, but not every department uses it.”

In other words, it’s a new technology that’s still being adopted. And, like ALPRs, it could soon be considered essential.

In a 2013 purchase request, the sheriff’s department called a software system that could apply facial recognition to mugshots “a mission critical program.”

The police purchase item was on the council’s consent agenda, so there was no discussion about it.

Accius hadn’t heard of ALPR technology prior to being contacted by SN&R, which he says is part of the problem. “You can’t make decisions without having the community be part of the process,” he said. “There’s still issues of trust.”

D’Arcangelew said municipalities can address this trust gap by having a robust public discussion before new technologies are deployed, and by ensuring proper safeguards are in place to protect people’s privacy.

The city’s Office of Public Safety Accountability, which monitors complaints against the police and fire departments, is attempting to broker a meeting between the ACLU and police department to discuss some of these issues later this month.

D’Arcangelew said the ACLU was initially contacted by community members who were concerned about the police department’s ShotSpotter detection system, which alerts police to possible gunshots. Depending on the model, she said the sensors could be picking up not just gunfire and sounds that resemble gunfire, but could also be recording conversations of people who think they’re speaking privately when the sensors are triggered.

“When you layer all these technologies—ShotSpotter and voice-recognition software, ALPRs and facial-recognition—they start to become really invasive,” she said.

OPSA Director Francine Tournour reached out to the ACLU after it contacted a city council member, she explained via text messages. “I thought it would be good for PD to hear their concerns,” she wrote.

A spokeswoman for the ACLU of Northern California said the group is still waiting on a confirmation date for the meeting.

Cruising northeast along the boulevard, digital images of rear-facing license plates flash across Hoertsch’s monitor, showing no criminal alerts.

In the old days—we’re talking President Barack Obama’s first term— a patrol officer would manually punch in the license plate information into a computer-aided dispatch, or CAD, and wait to see what came up. Prior offenses, open warrants, last-known address, the whole jacket. Before that, cops were reading the military alphabet into their walkies. And before that, cops were walking up on vehicles in total ignorance.

Now, they do less and know more.

Hoertsch started researching the technology in 2009, while he was doing hot-spot patrols at low-rent motels with the K-9 unit. Back then, he was running 300 plates by 10 a.m.—manually. In less than four years, he says the plate-readers have become as ubiquitous—and indispensable—as computers.

Hoertsch has since become the supervisor of his agency’s program, and a sought-after expert on the subject, telling agencies of the inventive applications that go far beyond the initial appeal: finding stolen vehicles.

“I don’t even talk about stolen cars,” he said. “The departments that are focusing on stolen vehicles are missing the other aspects.”

The license-plate scans perform what Hoertsch refers to as pre-records checks. By culling federal, state and local databases, the automated scans can notify officers within seconds of the location of a vehicle that has been reported stolen or is registered to someone who is a validated gang member, is prohibited from owning firearms, has a restraining order against them or any number of status identifiers that are either illegal or of concern to law enforcement.

All agencies that use ALPRs are subscribed to “premier” lists, curated by the California Department of Justice and FBI National Crime Information Center, which itself has 21 subsections regarding prohibited people and property.

Aside from those master lists, which feed alerts to patrol officers, the sheriff’s department has developed more than 20 of its own “hot lists” that it shares with surrounding police departments in the cities of Sacramento, Elk Grove, Citrus Heights, Galt and Woodland.

Some of these custom hot lists have been developed for vehicles registered to sex offenders, state parolees, local probationers, people with outstanding warrants and those on house arrest. The sheriff’s department is also beta-testing a hot list that will alert officers about registered vehicle owners with five or more DUIs.

These lists are automatically generated by cross-referencing known persons and criminal records databases. Wirelessly uploaded every morning, notification alerts are sent to any officer who’s signed up to receive them. An ALPR scan can trigger one of these hits within seconds, firing off an email or text to a parking-enforcement officer that a vehicle registered to someone on the “scofflaw list,” which is anyone with five or more unpaid citations, was scanned at a specific location in Fair Oaks, for example.

Back when Hoertsch was with the department’s sex-offender task force, he would receive approximately 80 to 100 emails a day.

The ACLU says it wouldn’t have an issue if the technology was only about hot lists.

“License-plate readers would pose few civil liberties risks if they only checked plates against hot lists and these hot lists were implemented soundly,” its report stated. “But these systems are configured to store the photograph, the license plate number, and the date, time and location where all vehicles are seen—not just the data of vehicles that generate hits.”

Hoertsch says such information can lead to crucial investigative breaks.

He recalled an armed robbery at a MetroPCS shop, one involving a suspect reportedly equipped with an AK-47, “obviously a pucker factor for law enforcement.” The victim recorded the license plate and a description of the fleeing vehicle. Prior to ALPRs, Hoertsch says, cops would mostly have to rely on the general description. “There’s an old cop joke that once you put out a suspect vehicle description, every car is that car,” he said.

Authorities ran the information through their database, finding two hits: The visual scan recorded three days earlier showed the license plate on a car that didn’t match the suspect vehicle’s description. The image recorded one day earlier did. That told officers the plate had likely been stolen. The suspect was ultimately apprehended.

In another case, the license plate scans helped prosecute a child molester. A 12-year-old boy had been molested by a family friend over a period of a year, Hoertsch says. The victim told authorities that one of the attacks occurred in a bathroom at Cal Expo during a soccer game. Investigators ran the defendant’s plate and discovered that it was scanned in the Cal Expo parking lot on that date, strengthening the prosecution’s case.

Hoertsch says the technology is also helpful in retracing the steps of reported missing persons, like when an 85-year-old woman went missing in the city of Sacramento. “That was all hands on deck,” he said. Pulling up images of the vehicle registered to her allowed officers to deduce her daily routine, and follow up with those places to see if anyone had seen her. The woman’s body was later located in a ravine, but other missing-person searches have gone better.

Civil liberties advocates say those anecdotal examples don’t change the fact that most of the information gathered doesn’t serve a specific law-enforcement purpose, but is being stored for long—sometimes indefinite—periods of time, anyway.

State and federal law are mum on how long license-plate information can be retained, leading it to wide disparities between agencies.

According to its public-records response, the police department stores information for five years, which is on the longer side of what the ACLU found in its own research—and longer than the city’s two-year limit for saving emails. Approximately 420 individuals and entities have access to this information.

The sheriff’s department retains license-plate data for two years, then flushes everything, Hoertsch said. That wasn’t an easy decision.

“The things we did wrestle with in our retention period was how long we should hold onto the information,” he said. “The photos are worth their weight in gold.”

The ACLU believes agencies should discard all vehicle information that doesn’t appear on a hot list and has called for other regulations. Last year, 32 states considered ALPR-related legislation. California adopted Senate Bill 34 last year, which restricts who has access to ALPR data and gives the public some recourse if the information is misused, but doesn’t address retention.

Along with Stingray cellphone tracking technology and the expanded use of biometric data in jails and on the street, the ubiquitous technology is a testament to the speed at which technological innovations outpace legal interpretations and limitations.

“Everything plays catch-up,” Hoertsch acknowledged. “Being a cop for 20 years, I’m not saying stuff hasn’t been abused,” he added. But, he contended, “This is so noninvasive … compared to what’s available. Even on Google searches.”

The Sacramento County Public Defender’s Office isn’t so sure. Supervising Assistant Public Defender Steven M. Garrett says there is still much his office doesn’t know about how ALPRs are used to build cases or justify arrests. “We’re seeing it more and we’re looking at it with a critical eye,” he said.

Accius says he finds it ironic that law enforcement keeps gathering more detailed information about the public without sharing in return. Local agencies have resisted public calls for random drug testing, the widespread adoption of body cameras and empowered police commissions.

“Why are we giving them all this access and they haven’t given us any access to them?” Accius said. “No reciprocation at all.”