Police are using surveillance tech to build cases in the dark. The ACLU of Massachusetts is finally handing lawyers the tools to shine a light on those secrets.
It starts with a simple, urgent need: criminal defense attorneys need a toolkit to uncover state surveillance. Not just for show. But to force prosecutors to admit if facial recognition, stingrays, or AI-drafted reports shaped the evidence against their clients.
This isn’t a theoretical exercise. It’s a war fought on two fronts.
Arming the Defense in the Courts
The group released an online resource this week. They call it the first of its kind. It is built around specific legal motions. When a judge grants these motions, prosecutors are forced to reveal if surveillance technology was used.
What is covered? Almost everything.
Stingrays that mimic cell towers. Location data sold by shady commercial brokers. Automatic license plate readers. Forensic tools that crack smartphones. Even software that sucks data from car infotainment screens. AI-drafted police reports are in there too.
There is also a preservation mechanism. It demands that agencies and private vendors save this data before it self-destructs. The strategy relies on a 1963 Supreme Court rule: prosecutors must turn over any evidence that helps the defense. These motions go into a password-protected library. Only verified defense attorneys can access them.
Jennifer Herrmann, an ACLU staff attorney and author, describes the fight clearly. Cities need to drop tools like Flock and ShotSpotter. That’s one front. The other is arming lawyers to expose what’s happening inside the courtroom.
“The amount of time that it can take for initial use of technology to actually get to a constitutional challenge is long.” — Jennifer Herrmann
These motions let attorneys challenge past actions. They build a record that sticks around when the next invasive tool arrives.
The Chronic Lag Between Adoption and Justice
There is a problem with timing. Police adopt new tools instantly. Courts take years to decide if those tools are legal.
Cell phones were everywhere by the late 90s. But it took until 2018 for the US Supreme Court to require warrants for cell location data. The lag isn’t just bureaucratic inertia. The tools with the worst transparency records face the fewest rulings. Why? Because defendants never know they are being watched. They cannot challenge a secret they were never told about.
The ACLU highlights how bad the secrecy has gotten. Police sometimes deploy these tools without even telling the prosecutors handling the case.
For years, the FBI forced local police to sign secrecy agreements to use cell-site simulators (stingrays). In Baltimore, one agreement explicitly told prosecutors to drop cases rather than reveal the device. The police used it 4,300 times between 07 and 15. The FBI kept the agreements until at least 202.
In Missouri, investigators used Fog Reveal for a 2017 murder probe. The Associated Press found zero trace of it in the trial evidence. The victim’s wife was still convicted.
In Louisiana, Randal Quran Reid was misidentified by facial recognition. He spent nearly a week in jail. The arrest warrant attributed the ID to a “credible source,” not software. The document that authorized his arrest actively hid the method of suspicion.
The Real Problem: Defense Lawyers Don’t Ask
The ACLU authors frame this slightly differently. It’s not just that evidence is hidden from prosecutors. It’s that defendants are never told a tool was used. Defense lawyers don’t know to ask.
Gideon Epstein, another author and policy counsel, points to a local precedent. In Commonwealth v. McCarthy, the defense only sought records for a handful of cameras. They missed the statewide network.
“A lot of the time they’re not asking for the full scope of surveillance technologies,” Epstein says. The motions are as much about prompting attorneys to demand everything as they are about forcing the government to comply.
Digital Evidence That Destroys Itself
The preservation motions tackle a subtler threat: evidence that deletes itself.
Consider Axon’s Draft One. It’s an AI tool that writes police reports. It discards the machine-written draft by design. An Axon manager told the EFF that this avoids “disclosure headaches.” California legislators disagree. They passed a law last year requiring agencies to keep the drafts.
Then there is Flock Safety. Its license plate reader network deletes footage after 30 days by default. Chicago’s ShotSpotter contract declares gunfire data the vendor’s property, not the city’s.
In both cases, the digital material needed to fight back can vanish before a defense attorney is even appointed. Or it can sit behind a vendor’s firewall, out of government reach.
Epstein is quick to note a contradiction. The ACLU generally wants data to disappear quickly. They are lobbying Massachusetts to cut retention from Flock’s default 30 days to just two days. But once someone is charged? That same data might be the proof of innocence. Preservation motions exist to protect that window.
Massachusetts Law is Leading the Way
If this sounds like pie in the sky, look at the local courts. Massachusetts’s highest court has spoken, twice.
In 2024, the Supreme Judicial Court permanently dismissed drug and firearm charges against a Boston man. Police had defied a court order to reveal fake social media profiles used to surveil him. These profiles used Black and brown avatars. Prosecutors are now barred from ever refiling those charges.
Last year, the court ruled defendants can demand a hearing. They can force prosecutors to prove ShotSpotter is accurate before the evidence reaches a jury.
These rulings explain why the toolkit leans on Massachusetts law. The state’s high court is years ahead of the federal one. It required warrants for cell phone data back in 201. The ACLU says this framework can be adapted elsewhere.
Why Now?
The timing isn’t random. Three weeks ago, the US Supreme Court made a major move. In a 6-3 ruling, they declared that geofence warrants constitute a “search” under the Fourth. These warrants force Google to identify phones near a crime scene. The Court sent the case back to lower courts to figure out the specifics.
The ACLU is dropping a geofencing motion directly into that unsettled legal waters.
The group wants feedback. Attorneys are asked to report back after using the motions in real cases. Herrmann says the goal is to put good lawyering “at the fingertips of every attorney.” To flag the gaps. To keep building the record.
One rhetorical question hangs over this whole mess. If the government can spy on us without telling us, can we really be considered innocent until proven guilty? Or just innocent until we know what we’re accused of?
We’ll see how it plays out in the docket. The toolkit is ready. The question is whether the courts are ready to listen.
