Boston police resume using license plate readers after accidental release of data

License plate readers can scan thousands of passing vehicles per minute.
Suzanne Kreriter/Globe Staff/File
License plate readers can scan thousands of passing vehicles per minute.

The Boston Police Department has resumed using license plate readers, which can scan thousands of passing vehicles per minute, after it accidently released a database of scanned vehicles in 2013 and then stopped the practice, according to documents obtained through a public records request.

The technology, which is used by law enforcement across the country to find wanted felons, missing persons, or even get unpaid tickets resolved, has been a point of contention between police and civil liberties groups, who say collected data can invade privacy and potentially chill free speech.

In December 2013, after accidentally releasing the database of scanned vehicles, Boston police took their scanners offline while police Commissioner William B. Evans reviewed the program.


The database, released in response to a public records request, showed the location, date, and time of each scan of more than 60,000 vehicles over a six-month period.

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Soon after halting the license plate scanner program, Evans told the City Council that the “license plate readers, obviously, weren’t being used the way that we had committed to use them.”

“We were collecting so much data that we weren’t even sure what we were collecting, honestly,” Evans said at a City Council meeting in April 2014.

Evans told the City Council at the same meeting that he would work with the American Civil Liberties Union of Massachusetts to address privacy concerns and revise the Boston Police Department’s license plate reader protocols.

The Police Department invited the ACLU to review its draft policyin April 2014. And among the ACLU’s recommendations was that police retain data for only 30 days, which the department made part of its new policy.


Evans finalized the new policy in October 2016, according to the documents. A Police Department spokesman said the license plate reader program was launched again in September 2017.

The new policy prohibits using license plate readers to harass or target people based on race, sexual orientation, or any other legally protected characteristic, or to infringe on First Amendment rights, according to the documents.

“We really limit it, and it’s just not an overly broad capture of data,” Evans said in a telephone interview with the Globe last week.

The head of a technology program at the ACLU of Massachusetts said the organization was glad to see the data retention period shortened, but would like to see several of its other proposals incorporated into the new policy, including a ban on sharing data with other law enforcement for noncriminal investigations and an independent audit process. The organization also expected police to consult more with the community, said Kade Crockford, director of the Technology for Liberty Program for the local ACLU.

“We were under the impression that before BPD restarted its license plate readers, there would be some kind of public announcement or communication to the City Council and the press,” said Crockford in an e-mail last week.


A spokeswoman for Mayor Martin J. Walsh said the Police Department did not consult his office before relaunching the scanners last fall, but it was not required to.

City Councilor Andrea Campbell, who has advocated for the council to play a more significant role in overseeing police surveillance technology, was also unaware of the new use of the scanners.

“We are not always looped into Administration decisions, especially where we have no direct oversight,” said Campbell in an e-mail.

Boston police are now using three license plate readers in areas with high crime rates or that might be potential terrorist targets, such as Copley Square and the Financial District. The commissioner said he has no plans to use additional plate readers.

The technology is being challenged around the country.

Last month, the top court in Virginia allowed a lawsuit to proceed challenging police storage of license plate reader data.

The Supreme Court of Kentucky ruled in February that the scanners do not violate motorists’ privacy rights. And a handful of other states have passed legislation regarding license plate readers.

Evans declined to provide local examples of cases in which the license plate readers have proved useful, saying that many such investigations might still be ongoing given the short period during which the readers have been operational.

But, he said, the department is open to providing reports about how the readers have proved useful in solving criminal investigations, another of the ACLU’s recommendations.

“I’ll gladly give reports,” Evans said. “We have nothing to hide.”

Contact Shawn Musgrave at