NACDL's Fourth Amendment Center offers direct assistance to defense lawyers handling cases involving new surveillance tools, technologies and tactics that infringe on the constitutional rights of people in America. The Center is available to help members of the defense bar in bringing new Fourth Amendment challenges.

 To request assistance or additional information, contact 4ac@nacdl.org.

(Pre-Search Instructions and Post-Search Reasonableness)

A Report by NACDL’s Fourth Amendment Advocacy Committee Reporter, Steven R. Morrison [Released July 2014]

The Fourth Amendment has entered the digital age. New surveillance technologies and programs — from GPS tracking devices to automated license plate readers to bulk data collection — have upended traditional law enforcement practices and created new challenges for defense lawyers. This report offers an overview of this symposium and the substantive areas of concern related to new technological and legal changes that impact Fourth Amendment protections in criminal cases. [Released June 2016]

In response to a series of high-profile police killings of unarmed people of color, law enforcement agencies across the country began adopting body cameras as a solution to requests for more transparency and accountability. In order to study the impact of body cameras on the rights of the accused, the National Association of Criminal Defense Lawyers established a Body Camera Task Force comprised of defense attorneys from across the country. [Released March 2017]

Presented by: Brian Pori, Assistant Federal Public Defender, New Mexico; and Sarah St. Vincent, Researcher/Advocate, US Program, Human Rights Watch

Presented by: Esha Bhandari, Staff Attorney, Speech, Privacy, and Technology Project, American Civil Liberties Union

Presented by: Clare Garvie, Sr. Associate, Georgetown Law Center on Privacy and Technology; Kaitlin Jackson, Attorney, Bronx Defenders; and Joshua Kroll, PhD, computer scientist, Postdoctoral Research Scholar, School of Information, University of California at Berkeley

This webinar was supported by Grant No. 2013-MU-BX-K014 awarded by the Bureau of Justice Assistance.

Presented by Matt Mitchell, hacker, civil rights advocate, and Director of Digital Safety & Privacy, at Tactical Tech (also known as the Tactical Technology Collective)

Presented by: Colin Fieman Assistant Federal Public Defender, Tacoma, WA; and Paul Ohm, Professor of Law, Georgetown University Law Center

This webinar was supported in part by Grant No. 2013-MU-BX-K014 awarded by the Bureau of Justice Assistance.

HOW IS A CELL PHONE’S LOCATION IDENTIFIED? A cell phone’s location can be detected through cell site location information (CSLI) or global positioning system (GPS) data. CSLI refers to the information collected as a cell phone identifies its location to nearby cell towers. CSLI from nearby cell towers can indicate a cell phone’s approximate location. With information from multiple cell towers, a technique called “triangulation” is used to locate a cell phone with greater precision. Cell phone location information can be “historical” or “prospective.”

Cell Site Simulator Primer.

ALPR Primer.

The National Association of Criminal Defense Lawyers provides amicus assistance on the federal and state level in those cases that present issues of importance to criminal defendants, criminal defense lawyers, and the criminal justice system as a whole. A selection of NACDL's amicus briefs that address the Fourth Amendment are offered below. 

Courts have long made it clear that agents can search the bags of people entering the country. For the past decade or so, U.S. Customs and Border Protection (CBP) has applied that logic to digital devices. NACDL members are uniquely exposed to abuse in this context: digita

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