Defendants should know when digital surveillance technology has been used to build the case against them. This toolkit will help their lawyers find out.

By Gideon Epstein and Jennifer Herrmann

Criminal defense attorneys routinely represent clients in cases in which law enforcement has used digital surveillance technologies—facial recognition, license plate readers, gunshot detection systems, cell-site simulators, and more. But police and prosecutors don’t always disclose information about their use of these and other technologies to the defense.

The consequences of this secrecy can be devastating for individual defendants and even for the larger public. That’s because when a criminal defendant doesn’t know a technology was used to investigate them, they lack the ability to challenge whether the surveillance technology was used fairly, accurately, or constitutionally.

Depriving the defendant of that opportunity, in turn, deprives the larger public of the privacy protections we would all benefit from if courts were to rule that police use of a particular kind of surveillance technology in a particular manner violated the constitution.

This gap between police use of novel surveillance tools and constitutional challenges to those techniques can enable police to engage in unconstitutional surveillance for many years before courts correct it.

For example, most people in the U.S. began carrying cellphones in the late 1990s. Thanks to advocates at the ACLU of Massachusetts, in 2014, the Massachusetts Supreme Judicial Court held that the Massachusetts Constitution requires police to obtain a warrant before acquiring cellphone location data, but it wasn't until 2018 that the Supreme Court ruled, in an ACLU case called Carpenter v. United States, that the same requirement applies nationwide under the federal constitution.

To help criminal defendants and their clients address that larger law reform gap, we’ve created a toolkit for lawyers. Our goal is to give attorneys practical models that will help them defend their clients in the face of expanding surveillance technologies —and protect all of us against intrusions on constitutional rights.

Below, we answer a few common questions about the project.

Over the past several years, we've seen law enforcement agencies across the country quietly incorporate powerful surveillance technologies into their investigations. In most cases, these technologies have not been regulated by lawmakers or evaluated by courts, leaving police and prosecutors to decide how to deploy them without any sort of democratic or constitutional guardrails.

At the same time, police are deploying these tools often without informing defense counsel, without obtaining proper authorization, and sometimes without even disclosing their use to the prosecutors handling the case. In such situations, the deck is stacked against the defendant, who may not even know to ask whether a particular technology may have been used in his or her case.

Even when defense attorneys know about a particular technology and suspect it may have been used in a particular case, lawyers are left fighting to obtain basic information about how their clients were identified or tracked, and the legal avenues to request relevant information are often not straightforward—especially because digital surveillance tools are technologically complex.

We created this project to give defense attorneys a practical toolkit: a set of model discovery and preservation motions they can adapt to cases involving specific surveillance technologies. And when defense attorneys don’t yet know what kinds of digital surveillance technologies law enforcement employed, the generalized model motion for digital surveillance technologies addresses requests for a variety of surveillance tools.

The models are grounded in constitutional law, Brady obligations (requiring the prosecution to disclose potentially exculpatory information), and Massachusetts Rules of Criminal Procedure.

These model motions were assembled to be useful right now, in real criminal cases.

These model motions are written to assist criminal defense attorneys practicing in Massachusetts, though the underlying constitutional arguments—rooted in core constitutional protections of privacy and due process—are broadly applicable across jurisdictions. Local discovery rules in other jurisdictions may be different, and should be reviewed by attorneys practicing in those states.

The toolkit includes model discovery motions addressing the following surveillance technologies, with a model discovery motion for generalized digital surveillance technologies for cases where specific technology has not yet been identified:

• Facial Recognition
• Automatic License Plate Readers
• Commercial Data Broker Databases
• Predictive Policing Technology
• ShotSpotter/Acoustic Gunshot Detection
• Stingrays/Cell-Site Simulators
• Social Media Monitoring
• Geofencing
• AI-Generated Police Reports
• Video Surveillance
• Surveillance Video Analytics
• Cellphone Extraction Technology
• Vehicle Telematics Access Devices
• Generalized Digital Surveillance Technologies (covering many of the digital surveillance technologies listed above above)

The toolkit also contains model motions for preservation of materials by government actors and third parties, to ensure that data regularly set for auto-deletion is available for the defense.

The short answer: if law enforcement identified your client, tracked their movements, or built a case against them using a digital surveillance tool, you can file the relevant motion.

The longer answer is that these technologies are often not disclosed in police reports or charging documents. To help determine whether such technologies were used, you can look for cases involving: rapid or “lucky” suspect identification; a lack of specificity in the arrest report pertaining to how your client was identified or located; arrests in areas with dense camera or sensor coverage; charges arising from location tracking or location data; or cases involving gang investigations, gunshot incidents, or large protests.

When in doubt, the generalized digital surveillance technologies discovery motion can be a useful starting point to determine what, if any, technology was used to surveil your client.

These model discovery motions are rooted in defendants’ constitutional rights. Both the United States Supreme Court and the Massachusetts Supreme Judicial Court have made clear that due process requires disclosure of material favorable to the defense, most famously in Brady v. Maryland.

In Massachusetts, this constitutional disclosure requirement is codified in Massachusetts Rule of Criminal Procedure 14(b)(2), which imposes broad mandatory disclosure obligations, including information that tends to cast doubt on the credibility or accuracy of any evidence the prosecution may introduce, establish deficiencies in the investigation, or suggest bias played a role in the case.

Information about surveillance technology error or false positive rates, demographic disparities, dragnet tracking, and surveillance conducted without a required warrant or in excess of legal authority is exactly that kind of material.

Surveillance data is often stored with short retention cycles—deleted days, weeks, or months after collection, depending on the type of surveillance technology. By the time a defense attorney is appointed and the case develops, critical data may be gone or set for upcoming deletion.

Filing preservation motions as early as possible puts the government and relevant third parties on notice that relevant data from digital surveillance technologies must be retained.

The two model preservation motions separately cover (1) government and law enforcement records and (2) third-party data held by vendors, technology companies, and other private entities.

We're not able to serve as defendants’ attorneys or to co-counsel with defense attorneys, and nothing in this project—the model motions, this Q&A, or any other materials—constitutes legal advice or creates an attorney-client relationship. These materials are offered as educational resources and litigation tools for criminal defense attorneys.

With that said, we're happy to hear from attorneys who are using these motions, who encounter novel legal issues, or who want to share results—wins or losses. Feedback from practitioners is how this project improves.

Send any questions or comments to techmotions@aclum.org.

The model motions are available through a password-protected resource page accessible to verified criminal defense attorneys. To request access, email techmotions@aclum.org with information verifying your work as a criminal defense attorney.

We'll send you the access code along with more information about each of the digital surveillance technologies covered and guidance on how to adapt the motions for your cases.

Gideon Epstein is Technology for Liberty policy counsel and Jennifer Herrmann is a staff attorney at the ACLU of Massachusetts.