The Fremont Police Department has been quietly expanding its surveillance programs, sometimes without the knowledge of the City Council.

And although police say the goal is to reduce crime by using their growing arsenal of license plate readers and video cameras to quickly catch “prolific offenders,” they acknowledge the department doesn’t track the number and kind of crimes being solved with their high-tech tools because it would require too much work.

That concerns privacy advocates who say all that surveillance needs to be justified with data about its effectiveness.

“Law enforcement needs to explain to the public exactly what specific goal they are seeking to achieve with these technologies,” Matt Cagle, a technology attorney with the Northern California chapter of the American Civil Liberties Union, said in an interview.

“Public safety in the digital era requires transparency and oversight,” Cagle added. “And the sort of ‘just trust us’ approach to conducting surveillance of communities is not something that residents buy these days.”

Dave Maass, a senior researcher with the Electronic Frontier Foundation, agreed in an interview Fremont police should show an actual need for additional surveillance technology that can be abused to invade people’s privacy.

“We are talking about a technology that if you put enough cameras up in a city, you can track somebody in real time,” Maass said.

“And is Fremont getting to that point where they can just decide there’s somebody they want to keep an eye on, without any probable cause, without any warrants, and just get an alert every time they pass a camera?”

Not that Fremont is alone, Maass said. “Police around the country are acquiring more and more surveillance technologies each year, especially license plate readers and similar mass surveillance technologies. This growth is occurring even when there isn’t a commensurate rise in crime or other public safety threat that needs to be addressed.”

In 2015, the Fremont City Council authorized its police department to spend $300,000 to buy and install 12 automated license plate readers and more than a dozen video cameras to be placed at 10 locations, mostly near highway on-ramps.

But between June 2017 and June 2018, the department also spent about $113,000 to buy 14 additional mobile automatic license plate readers without the City Council’s knowledge or public input.

Because those purchase orders — obtained by this news organization — amounted to less than $100,000 each, then-police chief Richard Lucero and then-city manager Fred Diaz signed off on them without having to flag the City Council.

Four of the readers have since been installed on an unmarked police SUV and two each are planned for four marked patrol cars. The department also bought a mobile speed trailer that disguises two license plate readers police want to deploy at crime “hot spots.”

After receiving inquiries from members of the public and this news organization about the purchases, the department held a community meeting Sept. 25 to provide a “demystification” of its technologies. Police officials told roughly 75 people about the purchases and plans to eventually have at least one license plate reader-equipped patrol car on duty 24 hours a day.

They also gave a few examples of how they used the tools to make arrests in three cases, including a murder at a Fremont hotel in October 2017.

Det. Jason Valdes displayed images captured by license plate readers and video cameras of a car arriving at the hotel just before the murder and leaving quickly afterwards.

By following up on the license plate registration information, officers arrested three suspects “in less than 20 hours after the homicide occurred” and collected several pieces of evidence, he said.

“Without the use of the cameras, the suspects would have never been identified and arrested so quickly, and the evidence may have been lost forever,” Valdes said.

The success stories are anecdotal, however. Lt. Mike Tegner told the crowd police stopped keeping track of how often the cameras and readers have led to arrests after the first six months of installation.

“We do get asked a lot, regarding can we quantify our successes,” Tegner said. “Can we give a number of how many times we’ve solved crimes using community camera LPR, or video? We just can’t give that because literally it would be an inaccurate number because every investigation pretty much involves them, at one time or another getting onto either the video or the LPR data to try to solve the crime.”

The mobile readers constantly scan license plates that pass by patrol cars, checking them against “hot lists” and pinging an officer when a plate matches that of a stolen car or an Amber alert, for example, police said.

Fremont police spokeswoman Geneva Bosques said tracking all that information isn’t easy. “It would be an enormous amount of work for a staff person to try and track every case that a community camera or a LPR is being used in,” Bosques said in an email.

Bosques said initial stats on the use of readers and cameras were compiled manually, but that became more difficult as the number of cameras and officers using them increased.

“To manually read through every report or have to follow up with every officer to see if they used the system to investigate a incident, is just not feasible at this point in time,” she said.

If crime statistics alone were used to gauge the success of license plate readers, the conclusion would be mixed. In 2017, the first full year license plate readers functioned around the city, burglaries dropped by 27 percent, according to state crime records. However, violent crime including robbery rose slightly, the number of cars stolen climbed more than 8 percent and burglarized cars jumped 36 percent.

While video camera footage is stored locally for 30 days before being purged, all license plate reader data from the city is sent to the Northern California Regional Intelligence Center in San Francisco and stored for one year.

Once in the database, it can be accessed by other law enforcement agencies in the region, as well as some federal agencies, including the Immigration and Customs Enforcement, or ICE, according to intelligence center officials.

In a one-year period between August 2017 and July 2018, Fremont license plate readers sent nearly 20,000,000 plate scans to the intelligence center, according to data obtained by this news organization from Dan Mahoney, a deputy director of the center.

“How many crimes are they solving with year-old data? That’s some of the information that needs to come to light,” Electronic Frontier’s Maass said. “Is it actually proportionate to the public safety need to collect so much data on people?”

City council members overall said they support the expanded use of the technology, even though the recent purchases had been made without their knowledge. Mayor Lily Mei did not respond to multiple requests for comment.

Councilman Rick Jones, a retired Fremont cop, said the cameras and readers are “a huge investigative tool” that benefits public safety, so he supports them.

“You’re going to have some people who are going to be into the numbers; how many did it record, how many did it lead to a crime being solved?,” he said.

“I’m not a big numbers person. If it’s successful, it’s successful,” Jones said. “If it solves one crime, it’s worth the expense.”