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Criminal Defense Resources


Criminal Defense Resources

As law enforcement acquires new technologies for surveillance in criminal investigations, the threat of unprecedented governmental access and intrusion into clients’ digital lives grows exponentially. EFF aims to arm criminal defense attorneys with the information and tools they need to rein in state invasion into their clients’ digital privacy. 

EFF is always looking for opportunities to support criminal defense attorneys with cases where issues related to these technologies arise. If you have a case in which you would be interested in amicus support, please contact or Please provide the case name, number, jurisdiction, stage of the proceedings, and any pending deadlines for amicus filing.

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Automated License Plate Readers

Automated license plate readers (ALPRs) are high-speed, computer-controlled camera systems that are typically mounted on street poles, streetlights, highway overpasses, mobile trailers, or attached to police squad cars. ALPRs automatically capture all license plate numbers that come into view, along with the location, date, and time. The data, which includes photographs of the vehicle and sometimes its driver and passengers, is then uploaded to a central server. (Read our guide

 How do I fight ALPR?

  1. File a Motion to Suppress – unverified ALPR hit alone (i.e. software match without visual confirmation) may not justify a stop. (Green)
  2. Persistent ALPR use to track a person over a prolonged period of time may implicate 4th Amendment protections and should arguably require a warrant supported by probable cause. Analogize to United States v. Jones, 565 US 400 (2012) & Cell Site Location Information cases. 
  3. In some states, ALPR use must meet statutory requirements. Some state laws may provide suppression remedy for statutory violations:

 Review the License Plate cases:

  1. U.S. Court of Appeals for the Sixth Circuit: United States v. Ellison (462 F.3d 557 (2006)): No reasonable expectation of privacy in license plate numbers.
  2. Georgia Court of Appeals: Hernandez-Lopez v. State (319 Ga. App. 662 (2013)): Court held that an ALPR hit indicating an outstanding warrant created reasonable suspicion to justify a traffic stop.
  3. U.S. Court of Appeals for the Ninth Circuit:
  • United States v. Diaz-Castaneda (494 F.3d 1146 (2007)): Court noted consensus among the circuits that single-instance ALPR database check is not the equivalent of a search.
  • Green v. City and County of San Francisco (751 F.3d 1039 (2014)): Court held that genuine issue of material fact existed as to whether officer had reasonable suspicion to make a stop despite an ALPR hit.

    Face Recognition


    Face recognition is a method of identifying or verifying the identity of an individual using their face. Face recognition systems can be used to identify people in photos, video, or in real-time. Law enforcement may also use mobile devices to identify people during police stops. (Read our guide

    Some factors that may indicate law enforcement used facial recognition:

    1. An officer or witness took your client’s photo before booking
    2. Your client was arrested in an unusual location or without notice
    3. Buzzwords to look for in reports:
    •  “photos from a police database”
    • Next Generation Identification-Interstate Photo System (“NGI-IPS”) – FBI database of nearly 73-million criminal records and over 53-million civilian records
    • Facial Analysis, Comparison and Evaluation (“FACE”) Services – over 411-million non-criminal photos from driver licenses & passports
    • Universal Control Number (“UCN”) – ID number assigned to photo
    • Repository for Individuals of Special Concern (“RISC”)
    •  “Candidate List” – list of potential matches

    How do I challenge face recognition evidence?

    1. Subpoena contract between the law enforcement agency, the U.S. Department of Justices, and the face recognition program developers to review limits in programming capabilities.
    2. Object to error rates and false positives: NGI purports to provide the “true candidate” in the top 50 profiles only 85% of the time–and that’s presumably only if the “true candidate” is even contained within the database–leaving the system prone to false positives.
    3. Consider filing a motion to compel the face recognition algorithm source code to search for flaws that may affect search results.
    4. If in Illinois and a stock photo is taken from a private actor, take advantage of the Illinois Biometric Information Privacy Act that requires notice and consent before use of face recognition technology.

    Drones/Unmanned Aerial Vehicles

    Drones are unmanned aerial vehicles that can be equipped with high definition, live-feed video cameras, thermal infrared video cameras, heat sensors, radar and other technologist—all of which allow for sophisticated and persistent surveillance. (Read our guide

    Drone laws

    1. Some state statutes limit use of drones by public entities, private individuals, or both. Some states permit police departments to attach lethal or nonlethal weapons to drones.
    2. For a list of drone laws by state:
    3. There is little clarity about airspace usage rights under 400 feet, the FAA’s altitude limit for small-drone operators. Though historically, the air above a property was often considered to be part of that property, the U.S. declared anything higher than 500 feet public airspace in the 1950s.

     Drone and drone-related cases:

    1. FAA regulations were triggered in part by the 1946 Supreme Court decision in United States v. Causby, 328 U.S. 256 (1946), in which a chicken farmer sued the government to limit military flights over his property. SCOTUS held that military flights over private property was a physical invasion akin to a regulatory taking, which suggests that operating a drone over private property may constitute trespass.
    2. U.S. District Court for the District of Connecticut: Huerta v. Haughwout, No. 3:16-CV-358, 2016 WL 3919799, at *4-5 (July 18, 2016): Court grants order enforcing FAA subpoenas to investigate allegations of weaponized drone use by private drone operators.
    3. U.S. District Court for the Western District of Kentucky: Boggs v. Merideth, No. 3:16-CV-00006-TBR, 2017 WL 1088093, at *5 (March 21, 2017): Court dismisses civil suit by drone operator against his neighbor for shooting down his drone while it was flying over his neighbor’s property. 

    Body-Worn Cameras

    Body-worn cameras (BWCs) are small cameras which can be clipped onto a police officer’s uniform or worn as a headset and turned on to record video and audio of law enforcement encounters with the public. The video is often saved with time and date stamps and GPS coordinates. (Read our guide

     How do I obtain body-worn camera footage?

    • BWC footage should be available through discovery, although depending on the state, prosecutors may not be required to produce footage at a pre-trial detention hearing. See Robinson below.
    • Private parties, including journalists, may request BWC footage through public records act requests.

     How do I challenge the use of BWC?

    1. BWC footage is subject to the same limitations as a police officer’s visual observations. If police presence is found to be illegal, such as entering private property without a warrant, you can move to suppress.
    2. Also, applying facial recognition or other biometric techniques to body camera footage may constitute a Fourth Amendment search requiring probable cause.

     Some BWC cases:

    1. U.S. District Court for the Southern District of New York: Floyd v. City of New York (959 F. Supp. 2d 668 (2013)): Court ordered NYPD to adopt pilot BWC program to remediate discriminatory stop-and-frisk policy.
    2. Supreme Court of New Jersey: State v. Robinson (2017 WL 1908548 (May 10, 2017)): Court held that New Jersey state law did not require production of existing BWC footage at pre-trial detention hearing.


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