Court Ruling Challenges Warrantless Flock Camera Searches

Estimated Time to Read: 11 minutes

A federal court in Oklahoma has added a significant new ruling to the debate over automated license plate readers (ALPRs) and the Fourth Amendment.

In United States v. Kyle, U.S. District Judge Sara E. Hill ruled that a sheriff's deputy's warrantless search of a driver's historical ALPR data violated the Fourth Amendment. The search gave the deputy more than 50 records of the vehicle's location across multiple states over roughly a month.

The decision does not settle the constitutional question, and the court acknowledged that other courts have reached the opposite conclusion. What it does is confront a question that grows harder to ignore as ALPR networks expand: Is there a meaningful difference between seeing someone's vehicle on a public road and reconstructing weeks of that vehicle's movements with a database search?

Judge Hill concluded that there is.

The Case in Brief

The case began with a traffic stop in Oklahoma. Tulsa County Deputy Sheriff Freddie Alaniz, parked along a highway, noticed a Mazda SUV with a California plate and ran it through Flock, one of at least two ALPR systems his patrol car could query. Those systems gave him at least 30 days of location data from numerous states. According to the court, the California plate was all he knew when he searched it. The results traced the vehicle toward the California-Arizona border and back toward Missouri.

Alaniz then stopped the driver for following another vehicle too closely, which Judge Hill found lawful. He went on to extend the stop into a drug investigation based on a short trip to California, several bags, a rental car, a cigarette, and visible nervousness. The court found those were ordinary features of travel rather than reasonable suspicion, and it suppressed the evidence from the extended stop.

Judge Hill then ruled separately on the ALPR query itself. "The only reason Alaniz conducted that search was that he saw her license plate was from California," she wrote. With no warrant and no probable cause, she held the search unconstitutional and suppressed the evidence that flowed from it.

When Does an ALPR Search Become Surveillance?

The government's argument was familiar. A license plate is displayed publicly, a vehicle on a public highway can be seen by anyone, and drivers cannot expect their presence at a particular place on a public road to remain private.

Judge Hill did not dispute that premise. She focused instead on what happens when thousands of individual observations are collected, stored, connected, and made searchable.

The "no privacy in public" argument traces largely to United States v. Knotts (1983), in which the Supreme Court approved warrantless use of a radio beeper to follow a container over a few hours of highway travel. As Reason recently explained, the Court has since moved well beyond that principle. In United States v. Jones (2012), it held that attaching a GPS tracker and monitoring a vehicle for 28 days was a search, and five justices wrote separately about how much a month of movements can reveal.

The court acknowledged that neither the U.S. Supreme Court nor the Tenth Circuit has decided whether law enforcement's use of ALPR technology is a Fourth Amendment search, and that nearly every court to consider the issue has concluded it is not, because movements on public streets generally are not private. Judge Hill found that approach hard to square with modern surveillance technology and with the Supreme Court's location-data decisions. Her ruling relied heavily on the principle recognized in Carpenter v. United States and, this summer, Chatrie v. United States: people can have a reasonable expectation of privacy in the whole of their physical movements, even when portions of those movements occur in public view.

Chatrie is especially relevant. As Texas Policy Research (TPR) noted when it was decided, the Supreme Court rejected the government's argument that two hours of location data was too little to raise a constitutional concern. If a few hours of location history can warrant protection, the government has a harder time arguing that a month of it does not.

Judge Hill described the systems behind the search, which give law enforcement a continuously updated history of every vehicle their cameras capture, as "a type of indiscriminate mass surveillance."

She illustrated the point with a simple comparison. Someone might reasonably expect a friend to mention seeing their car near a store. What people do not expect is for someone to approach them with a photo-backed record of everywhere their vehicle has appeared for the past 30 days. "Freedom from persistent, dragnet-style surveillance while in public is not a foreign concept in our society," the court wrote.

The concern is what such a record can reveal. Judge Hill noted that historical ALPR data could show visits to a fertility clinic, liquor store, casino, doctor's office, or attorney's office, or simply document someone's daily commute. No single trip is necessarily private. The intrusion comes from the government's ability to assemble them into a detailed picture of a person's life without ever physically following that person.

The opinion put the point most directly in a single question: "why is it the government's business where everyone goes all the time?" Judge Hill answered that government cannot simply snoop through people's personal lives without an adequate basis, and that "it is not too much to draw the line at indiscriminate mass surveillance."

What the ALPR Ruling Means and What It Does Not

Kyle is a federal district court decision from Oklahoma. It does not create a nationwide warrant requirement for ALPR searches, and it does not bind courts in Texas.

In fact, the Fifth Circuit, whose decisions do govern federal courts in Texas, reached the opposite result earlier this year. In United States v. Porter, decided in March, the court held that officers' use of license plate reader data to locate a vehicle was not a Fourth Amendment search. It distinguished Carpenter on the ground that cell-site records track a phone continuously, while an ALPR captures only a snapshot of a vehicle at a discrete moment on a public road.

The two cases are not as far apart on the facts as their outcomes suggest. Porter involved a plate captured at a specific intersection. Kyle involved a month of sightings across several states, assembled by a query with no suspicion behind it. That difference in duration, scale, and searchability is where the constitutional debate is moving. Porter was also decided before the Supreme Court's ruling in Chatrie, and Porter has asked the Supreme Court to review the Fifth Circuit's decision.

Why Kyle Matters for Texas

The search in Kyle was run by an Oklahoma deputy pulling data from cameras across several states. Texas cameras sit on the same kind of interconnected network. A Texas Tribune analysis of roughly 615,000 searches of the Texas Department of Public Safety's (DPS) camera network in June found that 48 percent came from outside Texas, with more than 3,000 agencies querying the system. DPS has since restricted outside access, but the episode showed how readily Texans' movements can become the subject of the kind of query Judge Hill found unconstitutional.

Gov. Greg Abbott (R) has slowed the network's growth. In August, he halted state funding for additional Flock cameras, and in September he directed the Texas Department of Transportation (TxDOT) to stop approving new ALPRs on state roads. Neither directive removes existing cameras or sets rules for how the data they collect may be searched, retained, or shared. Kyle is a case about the search, not the camera, and the search is exactly what Texas law does not yet address.

The Legislature has had proposals before it. During the 89th Legislative Session (2025), State Rep. Brian Harrison (R-Midlothian) filed House Bill 961 (HB 961), which would have generally required a warrant or court order for law enforcement use of ALPRs. That is essentially the line Judge Hill drew. State Rep. John Bucy III (D-Austin) filed House Bill 2083 (HB 2083), which would have permitted specified uses while generally requiring captured data to be destroyed within 48 hours. Neither received a hearing in the House Committee on Homeland Security, Public Safety & Veterans' Affairs.

Texas lawmakers do not have to wait for the U.S. Supreme Court to define the constitutional minimum before deciding what protections Texans should have, particularly while the controlling precedent in Texas's federal circuit points the other way. As TPR has argued, the 90th Legislature should consider the full range of options, including whether government should operate networked ALPR systems at all. If some use continues, it should come with clear statutory limits on warrants, retention, sharing, auditing, and penalties for misuse. The alternative is leaving those boundaries to vendors, individual agencies, and courts applying doctrines developed before surveillance at this scale was possible.

What Kyle Signals for the Future of ALPRs

The most durable lesson of Kyle may be that the constitutional problem lies less in the camera than in the archive. A real-time alert that a stolen car just passed an intersection tells police where a vehicle is now. A query into weeks of retained sightings tells them where a person has been. Courts that accept the first while scrutinizing the second would leave room for targeted uses while drawing a line at historical tracking.

That makes retention the policy lever that matters most. If an agency keeps sightings of vehicles tied to no investigation for 48 hours, as HB 2083 proposed, there is no month-long history to search. If it keeps them for a year, every plate becomes a potential Kyle query. Some Texas cities already see this: Amarillo recently cut its retention period to seven days and tightened its auditing rules.

The ruling also puts a spotlight on why a search happens. Judge Hill's analysis turned partly on the deputy having no reason beyond an out-of-state plate. Requiring officers to record the basis for every historical query, and auditing those records, would make such searches visible rather than routine.

Finally, network sharing raises the stakes for everyone. Privately operated systems let data collected in one community be searched by agencies hundreds of miles away, as both Kyle and the DPS search figures show. Rules written one city at a time cannot control who queries a national network, which is why the question belongs at the state level.

Collect First, Suspect Later

Following someone's movements for weeks once required officers, time, and money. Those costs forced government to decide whom it wanted to watch before watching them. As TPR explored earlier this year, technology has removed much of that friction. A large ALPR network inverts the old sequence: government can collect the information first and decide whom to investigate later.

The deputy in Kyle did exactly that. He suspected no crime when he searched a month of a stranger's travel history. He had an out-of-state license plate and a database that made the search effortless.

Judge Hill's ruling will not be the last word on ALPRs. But it frames the right question for Texas lawmakers. The issue is not whether license plates are visible on public roads. It is whether government should hold a searchable record of where Texans go, available to any officer with a reason as thin as a California plate.

---

---