Five days ago we wrote that the argument over license plate cameras turns on a question a police department cannot answer for itself: what happens to the data after it leaves town. Boston has now published the answer for its own pilot, and it is worse than the critics assumed. The city’s contract with Flock Safety said data sharing was switched off. Within three days of the cameras going live, other police agencies were reading Boston’s plate data anyway.
What the report says
The finding is in the city’s 2025 Surveillance Technology Report, which went to the Boston City Council on Monday. Boston ran 45 Flock cameras for 156 days, from April 1 to September 4 of last year, at no cost. “Within three days of initiating the Pilot, BPD became aware that other law enforcement agencies were able to access license plate and vehicle information,” the report states. It attributes the exposure to an error by Flock. “The contract clearly noted that data sharing was to be disabled, and BPD confirmed with Flock that settings were off for sharing.”
Over the five months that followed, the department fielded 77 requests from outside agencies for its Flock data. The list includes the United States State Department, the Bureau of Alcohol, Tobacco, Firearms and Explosives, the Drug Enforcement Administration, the Massachusetts State Police, the Maine State Police, and the police departments of Brookline and Watertown. The report does not say which requests were granted.
The second finding is about Boston’s own officers. An internal audit, written by Lieutenant Detective Justin Wood, counted 11,004 searches of the database during the trial. About half of them carried no case number tying the search to a criminal investigation.
Mayor Michelle Wu said the city has abandoned the platform. “When the toggles or the access controls are not able to be restricted in the ways that conform with that policy, we would not use that platform,” she said. Flock did not respond to WBUR’s request for comment. The company has previously said it has no contract with Immigration and Customs Enforcement.
Why this lands differently in Chelsea
Two numbers make Boston’s experience relevant here. Nearly half of Chelsea’s residents were born outside the United States. And the PROTECT Act, signed on August 5, bars Massachusetts police from asking about immigration status during routine work and from holding people on immigration detainers alone, with the state’s law enforcement guidance issued this month.
Those protections govern what Chelsea officers may do. They do not govern what a federal agency does with a plate read that reached it through a vendor’s settings. That was the theoretical objection when communities began cancelling. Boston’s report converts it into a documented event: a contract that prohibited sharing, a vendor that enabled it anyway, and three days during which the data was open before anyone noticed.
Cambridge, Framingham, Salem, New Bedford, Natick, Watertown and at least eight other Massachusetts communities have dropped Flock this year. Winthrop has kept its half dozen and added officer training and a quarterly internal audit. Boston is the largest department in the state to walk away.
Chelsea uses Flock, and has the policy Boston thought it had
When we wrote about this last week we said the public record did not tell us whether Chelsea operates license plate readers or whose they are. That was wrong, and the answer has been in the city’s own files since March. We have corrected the earlier article.
On March 10 the council’s Conference subcommittee went through the “ICE Out of Chelsea” petition from the LUCE Immigrant Justice Network point by point, with Police Chief Keith Houghton and City Solicitor Cheryl Watson Fisher at the table. The fourth of the petition’s proposals asked the city to stop sharing license plate data with out-of-state and federal agencies. The minutes record the answer:
“The police department utilizes the Flock license plate reading system, which they indicate has served an invaluable role in solving many of the City’s most recent homicides. The City has a policy in place that prohibits the sharing of license plate data with any law enforcement agencies outside the state of Massachusetts, including federal agencies.”
So Chelsea has both things: Flock cameras, and a written prohibition on sending the data to federal agencies or out of state. On its face that is a stronger position than most communities in the state, and stronger than what many of the cities that cancelled were operating under.
Boston’s report is what makes it worth a second look. Boston also had a prohibition. Boston’s was in a contract, the strongest form such a restriction takes, and the department confirmed with Flock that the sharing settings were off. Within three days the data was flowing anyway because of a setting on the vendor’s side. The lesson of Boston is not that policies are worthless. It is that a policy governs the police department, and the exposure happened somewhere the police department could not see.
The questions that remain
The March minutes answer what system Chelsea uses and what the sharing rule is. They do not answer the rest, and the rest is where Boston’s failure occurred.
How many Flock cameras does Chelsea operate, where, and at what annual cost? How long are plate reads kept when they match nothing? Has the city ever verified, independently of the vendor’s dashboard, that the out-of-state sharing setting is actually off, which is precisely the check Boston’s contract did not survive? Is a case number required to run a search, and does anyone audit the searches? Boston required one and got it about half the time across 11,004 searches, and nobody knew until an officer counted.
There is also the question the chief’s own answer raises. Houghton told the subcommittee the system has been invaluable in solving homicides. That is the strongest argument anyone makes for these cameras, and it deserves to be weighed rather than waved off. The cities that dropped Flock gave up a real investigative tool. The question is not whether the tool works. It is whether the city can prove the data goes only where it says it goes.
Police Chief Keith Houghton told the council at the May budget hearings that the department “is run on many different platforms,” with separate software and licensing for body cameras, for “our cameras within the city,” and for other systems. How Flock sits inside that, and who reviews it, has not been described in a public meeting since March.
The city has a Public Safety subcommittee, chaired by Councillor Lisa Santagate. Councillor Leo Robinson has already asked it to convene on scooter safety. Adding an audit of the plate reader program to that agenda would take one evening, and Boston has just published a template for what such a review turns up.