NYPD Developing Remote Thermal Concealed Gun Detectors

The New York City Police Department (NYPD) is working with the federal Department of Defense to develop thermal scanning technology capable of detecting concealed firearms.  The technology works by scanning the heat that a person’s body radiates and determining whether that heat is being blocked by a colder object, such as a firearm.

The technology currently works from up to 3-5 meters away, but NYPD wants to extend its range to 25 meters (82 feet).  The NYPD has not yet indicated exactly how it plans to use the technology.  Although it certainly has lawful, practical, and productive uses for police and others, the way police ultimately use this technology will no doubt raise some thorny privacy and legal issues.

The U.S. Supreme Court addressed the use of a similar thermal scanning device by police in Kyllo v. United States, 533 U.S. 27 (2001).  In that case, the Court held that it was illegal for police to use thermal imaging to determine whether a suspect was using the high-intensity lights associated with growing marijuana in his house.  The high court found this constituted a “search” under the Fourth Amendment, and that it was “presumptively unreasonable without a warrant.”  The thermal imaging device at issue in Kyllo functions practically the same as the “gun detector” technology sought by the NYPD.  But the Kyllo court made much about the technology being used to search the home; the legal analysis could change if the technology is used on individuals walking on public streets or in other contexts, such as commercial venues.

While using the “gun detector” on an unsuspecting public without any suspicion of criminal activity could be found unconstitutional under the Fourth Amendment, its validity is less clear in the context of an officer checking someone the officer intends to, and may lawfully, arrest anyway.  A whole host of questions arise because this new technology has the potential to encroach on the privacy of individual citizens: Do people have an expectation of privacy from thermal imaging devices in those items concealed on their person while in public? Could police use the technology to randomly examine passers-by on the street? What about on individual suspects that police can already lawfully search to determine whether they are armed? How far can an officer go in determining whether a person is armed before entering the zone of danger? And to what extent is use of the “gun detector” similar to a “Terry Stop” – named for the Supreme Court case that authorizes officers to pat down the outer clothing of a person for weapons if the officer has a “reasonable suspicion” that the person is involved in a crime – since it only reaches under the clothing? All of these questions and others must inevitably be considered by the courts.

This technology and the potential to abuse it raises serious concerns for self-defense civil rights activists, especially given New York City’s historic hostility toward the right to keep and bear arms.  In just the past few months, several people passing through the City’s airport with declared firearms in their checked bags have been charged with felonies for unwittingly violating the City’s stringent laws against carrying firearms.  All were arrested only after voluntarily bringing their firearms to the attention of law enforcement and requesting assistance.

We will continue to monitor the development and use of this technology and any litigation that may arise as a result.

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