The American Civil Liberties Union of Massachusetts says it is releasing a password-protected online toolkit for verified criminal defense lawyers that is meant to force a basic disclosure: whether police used surveillance technology to build a case.
The project offers model legal motions that attorneys can adapt and file in court. If a judge grants them, prosecutors would have to say whether investigators used tools such as facial recognition, automatic license plate readers, gunshot detection systems, stingray phone trackers, geofence warrants, commercial location data, AI-written police reports, phone-cracking systems or software that extracts data from car infotainment units.
The group says the toolkit, which it describes as the first of its kind, also includes preservation motions aimed at government agencies and private vendors. Those filings are designed to stop surveillance records from vanishing before the defense can examine them, which is a depressingly practical concern when vendors build deletion clocks into the product.
The disclosure fight
Jennifer Herrmann, a staff attorney at the ACLU of Massachusetts and one of the toolkit’s authors, said the group is working on two tracks: pushing cities to abandon systems such as Flock Safety’s license plate reader network and ShotSpotter gunshot detection, while also giving defense lawyers a way to challenge surveillance already used in criminal cases.
The legal premise is old, even if the gadgets are not. Since 1963, prosecutors have been required to disclose evidence that could help the defense. The ACLU of Massachusetts argues that rule breaks down when police do not tell prosecutors, defendants or defense lawyers that a surveillance tool was involved.
The secrecy problem is not theoretical. The FBI required local police departments for years to sign nondisclosure agreements before using cell-site simulators, commonly called stingrays, according to records obtained by the ACLU. In Baltimore, one agreement told prosecutors to drop cases rather than expose the device in court, while city police used the technology more than 4,300 times between 2007 and 2015, according to reporting cited by the group.
Other examples show the same pattern with newer tools. The Associated Press found no mention of Fog Reveal, a commercial location-data tool, in trial exhibits after Missouri investigators used it in a 2017 murder investigation. The Washington Post reported that a 2022 Louisiana arrest warrant for Randal Quran Reid, a Georgia man wrongly identified through facial recognition and jailed for nearly a week, referred to the identification as coming from “a credible source” rather than naming the software.
Evidence that can disappear
Gideon Epstein, Technology for Liberty policy counsel at the ACLU of Massachusetts and the toolkit’s other author, said defense lawyers often do not ask for the full universe of surveillance records. He pointed to Massachusetts’ license plate reader case Commonwealth v. McCarthy, where the defense sought records from only a small set of cameras rather than the statewide network.
The preservation motions address systems that shed data quickly or keep it outside government control. Axon’s Draft One, which generates police reports from body-camera audio, discards its AI-written first draft by design. An Axon product manager told the Electronic Frontier Foundation in July 2025 that the company made that choice to avoid disclosure problems for police customers and prosecutors. California lawmakers later enacted a law requiring agencies to retain the original drafts.
Flock Safety says its license plate reader footage is deleted after 30 days by default. Chicago’s ShotSpotter contract treated gunfire data as the vendor’s property rather than the city’s, according to reporting cited by the ACLU. Epstein said the group still supports short retention periods for surveillance data generally, including a push in Massachusetts to cut license plate reader retention to as little as two days, but said data tied to a prosecution may also clear a defendant.
Massachusetts courts have recently shown why these motions can matter. In 2024, the state’s Supreme Judicial Court permanently dismissed drug and firearm charges after police failed to turn over records about fake social media profiles used to monitor a defendant. The same court later ruled that defendants can demand a hearing requiring prosecutors to prove ShotSpotter evidence is reliable before jurors see it.
The ACLU says the motions are grounded in Massachusetts law but can be adapted elsewhere. The toolkit also includes a geofence motion, arriving shortly after the US Supreme Court ruled 6-3 that police conduct a Fourth Amendment search when they use a warrant to make Google identify phones near a crime scene.
This story draws on original reporting from WIRED.
