(Source: Kansas Sheriff Magazine, Fall 2026, Reprinted With Permission)
Automatic License Plate Readers (ALPRs) are black, oval shaped cameras which are powered by an attached battery and a solar panel. They are mounted either on patrol cars or on stationary poles placed next to a roadway. ALPRs capture high-speed photos of license plates that pass by the camera. Photos are uploaded to a wireless data network where the information is used for law enforcement purposes such as locating stolen cars or those involved in serious crimes. ALPRs are used by both government agencies and private businesses. American ALPR companies include Flock Safety, Axon, Motorola Solutions, ELSAG Leonardo, and Rekor Systems. This article will refer to all ALPRs as “Flock” cameras which is the current and common name used in litigation and in media stories.
Research into license plate recognition technology began in 1976 in the United Kingdom with the first street device deployment in 1979 at England’s Dartford Tunnel. Due to high costs and user difficulty, the technology did not reach the United States until the 1990s, and then only in larger cities. However, by the late 2010s deployment costs had dropped, user experiences had improved, and more law enforcement agencies began installing the equipment. The Flock technology has maintained a solid record of helping officers more quickly solve crime and arrest offenders.
Lately, and seemingly out of the blue, Flock cameras have landed in the news and in the courts. Why? Does a person have an expectation of privacy in their license plate on a public street? To better understand the controversy we need to first take into account factors other than the law: the current distrust of government institutions, the continuing rub between citizens voluntarily posting personal information on social media while at the same time demanding personal privacy, the ever-growing private and government surveillance in public places and events for better security, and the general backlash to ever-smarter computers, data centers, and the unknown future of artificial intelligence (AI). As computer scientist Alan Kay said about our digital fears, "[t]echnology is anything that wasn’t around when you were born."
As for the law, our courts have spent the last two generations trying to balance the Constitution’s 235-year-old Fourth Amendment with today’s ever-larger digital world. The court struggles have included defining new expectations of privacy in information that is now created and retained somewhere outside of the natural world. The law understands paper. But, the Cloud (whatever that is), not so much.
The Fourth Amendment provides that the “right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated.” The Big Court recognizes two types of government searches: 1) where a person has a subjective expectation of privacy in the area searched, and society finds such expectation to be objectively reasonable; and, 2) when the government commits a “trespassory search” such as when an officer physically places a GPS tracking unit on a car, or when an officer enters the curtilage of a home for criminal investigative purposes. Should the government’s action be deemed a search, then the government probably needs a warrant.
Created in the 1970s and known as the “third-party doctrine,” courts have held that a person has no reasonable expectation of privacy in information that they voluntarily provide to others, like records at their bank. That legal doctrine, once well understood and absolute, has lately been badly shaken because of our intimate use of cellphones.
Looking back, we should not really be surprised. For years now, the Big Court has been adding to the list of police investigative techniques for which officers now need a search warrant: thermal imaging equipment (2001), GPS trackers (2012), front door dog sniffs (2013), searches of cellphones during arrests (2014), third-party cell-site records (2018), and just a few months ago, “geofence” third-party cellphone location records (2026). The thread running through those cellphone cases is that there still is no expectation of privacy in third-party records . . . except when there is.
A note to remember is that the very strong current law that holds that there is no expectation of privacy in publicly-displayed license tags is all pre-Chatrie v. United States, (the 2026 Big Court “cellphone location records are private” case). So, what the effect Chatrie will have on Flock systems, if any, is currently unknown. Hopefully, the Big Court will soon agree to hear United States v. Porter, No. 26-5121, a 5th Circuit case pending certiorari that presents this exact question.
Mosaic Theory: At one time, raising an argument that a person could ever have an expectation of privacy in their publicly-displayed license plate would have been found beyond frivolous. And, that remains the law today. That said though, for some years there has been an idea bouncing around courtrooms called “Fourth Amendment Mosaic Theory.” Like a glass mosaic made up of hundreds of pieces of colored glass, the theory holds that the government currently has the ability to gather bunches of small anonymized pieces of digital data (like colored glass) about a person that when placed together into a larger picture can reveal a person’s entire identity or habits. Proponents of the theory believe that such a collective governmental effort should require search warrants for the seizure of each of those smaller pieces of digital data because of what they call today’s “permeating police surveillance.” In other words, the “whole is greater than the sum of its parts.” So, a Flock record is allegedly simply another piece of colored glass for a citizen’s mosaic.
Misuse of Flock: Admittedly, license plate reader opponents have a few valid concerns. They point to 1) the unnecessary and lengthy retention of most Flock records; 2) the lack of internal and external verifiable audits of agencies’ Flock systems; and, 3) the misuse of the systems by a few officers, usually to further the rogue officers’ personal domestic disputes. In response to those concerns:
- Retention time of Flock records should be at an absolute minimum unless particular records are needed in an identifiable and verifiable investigation. Requiring a supervisor to approve any retention of Flock records should be considered. Some proactive agencies are now automatically discarding unneeded Flock information within 3-7 days. The fewer days probably the better.
- Agencies should be periodically self-auditing their systems for misuse. It may be wise to legislatively assign such audits to a particular state agency that already has system auditors in place performing audits for other governmental computer, radio, and information systems.
- The Kansas state agency charged with investigating police misconduct (CPOST) has recently revoked two law enforcement officers’ certifications for misuse of Flock information. A third case is awaiting resolution of a parallel criminal case. Requiring some type of periodic internal or external system auditing, and mandating proper-Flock-use training should help prevent future misuse cases.
The Current Kansas Flock Case: Mason Grimmett v. City of Wichita, Kansas, SG-2026-CV-002760, a Petition for Declaratory Judgment, filed July 29, 2026 by the Kansas Institute of Justice.
Grimmitt “challenges the government’s indiscriminate and warrantless dragnet surveillance of anyone, and everyone, driving in the City of Wichita. Through its vast and pervasive network of automated license plate readers, Wichita is continuously tracking, surveilling, monitoring, and compiling a searchable database on law-abiding Kansans -- without a warrant, without probable cause, without reasonable suspicion – without even so much as a hunch – it’s all done without any judicial oversight whatsoever.”
Somewhat surprisingly, Grimmitt does not argue direct federal Fourth Amendment protection. Instead, he asks the district judge to declare that the City’s license plate reader program violates Section 15 (search and seizure) and Section 20 (unenumerated rights) of the Kansas state constitution. As remedies for such violations, Grimmitt seeks a permanent injunction against the Flock program and deletion of all Flock records; or, in the alternative, to allow himself and other similarly-situated persons to “opt-out” of the Flock program.
Last, but not least: in addition to the routine “expectation of privacy” argument, Grimmitt asserts that the Flock system is a “trespassory search.” That is because state law requires every vehicle to have affixed to it a government-issued license plate. Such a government-required plate, coupled with the government-deployed Flock system, results in the “functional equivalent of affixing a GPS tracking device on every car.” Grimmitt says “[w]hether it’s a GPS tracker or a license plate, Wichita conducts a physical trespass, and both are now used to obtain the same information: the long-term tracking of one’s movements.” That, my friends, is very imaginative, but is legal nonsense . . . maybe.
Bottom Line: Does Flock gather too much information? How much information is too much information? Do agencies retain Flock information for too long? How long is too long? Should agencies do a better job of auditing the records that they obtain? How and by whom should such audits be done?
Ultimately, we as a society will need to decide how much personal privacy in public places we are willing to trade for greater personal security through better crime control. That two-century-old debate continues.
For further research and understanding: United States v. Knotts, 460 U.S. 276 (1983)(person traveling in car on public thoroughfares has no reasonable expectation of privacy in his movements); Kyllo v. United States, 533 U.S. 27 (2001)(thermal imaging equipment requires warrant); United State v. Jones, 565 U.S. 400 (2012)(GPS tracker requires warrant); Florida v. Jardines, 569 U.S. 1 (2013)(dog sniff on curtilage at front door is a search); Riley v. California, 573 U.S. 373 (2014)(cellphone search during arrest requires warrant or consent); Carpenter v. United States, 585 U.S. 296 (2018)(cell-site records require warrant); Chatrie v. United States, 609 U.S. (2026)(cell-location “geo-fence” records are a search, require particularized warrant); United States v. Porter, 170 F.4th 381 (5th Cir. 2026), petition for cert filed, No. 26-5121 (LPR system not comprehensive tracking and not a search); United States v. Matthews, 615 F.2d 1279 (10th Cir. 1980)(no expectation of privacy in license plate exposed to public); United States v. Jackson, 2025 WL 1530574 (D.Kan. May 29, 2025)(Flock is a “stark contrast” from continuous and personally invasive data in Carpenter).
10/20/2026 NOTE: Since this article was written in September, a federal district court judge in the Northern District of Oklahoma has held that the use of Flock in a criminal investigation was violated the defendant’s reasonable expectation of privacy. I would expect the government to appeal that decision to the 10th Circuit Court of Appeals. See United States v. Melisa Susan Kyle, 26-CR-00189-SEH, (ND.Okla., October 1, 2026).
~ Colin
