When Does Smart Policing Become a Fourth Amendment Search?

A Look at Cellphone Tracking, Flock Cameras, and the Growing Legal Limits on Technology-assisted Policing. 

A child has been abducted. Police know the make and model of the suspect's vehicle, but not where it went. Within seconds, roadside cameras can search thousands of photographs and may locate the vehicle.

Shots are fired in a neighborhood, and no one calls 911. Sensors can identify the sound as probable gunfire, estimate its location, and alert officers in less than a minute.

A murder suspect drives across the country. License plate photographs, surveillance cameras, and cellphone records can help investigators reconstruct his movements long after they occurred.

Few would question the public-safety value of these tools. Their growing capabilities, however, raise a harder question: At what point does technology become so powerful that collecting otherwise public information becomes a search under the Fourth Amendment?

That question becomes increasingly important as artificial intelligence allows law enforcement to collect, search, and analyze enormous amounts of information. A photograph of a car on a public road reveals little. A network capable of reconstructing weeks of a person's movements may reveal considerably more.

Several recent decisions, including cases involving Virginia police departments and Flock Safety cameras, illustrate how courts are drawing that distinction. They also show that the constitutional limits of modern surveillance remain unsettled.

Your Phone Is Private. Your License Plate May Be Different.

Cellphone-location information provides a useful starting point.

In June 2026, the United States Supreme Court decided Chatrie v. United States, 609 U.S. ___, 146 S. Ct. 2193 (2026). Police investigating a credit union robbery in Midlothian, Virginia, obtained a geofence search warrant directing Google to provide location information about phones within approximately 150 meters of the crime scene. Google's records eventually identified Okello Chatrie.

The Supreme Court held that obtaining those records constituted a Fourth Amendment search. Individuals have a reasonable expectation of privacy in their cellphone-location information, even when a technology company stores the data and investigators request records covering only a relatively short period.

The Court did not decide whether the particular geofence warrant satisfied the Fourth Amendment. Instead, it returned the case to the Fourth Circuit to evaluate the warrant's probable cause and particularity requirements.

Nevertheless, the central holding is clear: Police access to the type of location information involved in Chatrie implicates the Fourth Amendment.

In September 2026, the Fourth Circuit reached a similar conclusion concerning a different investigative tool. In Andrews v. Baltimore City Police Department, 2026 U.S. App. LEXIS 29401 (4th Cir. Sept. 24, 2026), officers used a cell-site simulator that imitates a cellphone tower. The device causes nearby phones to transmit identifying signals, allowing officers to locate a particular phone in real time.

The Fourth Circuit held that this use of a cell-site simulator constituted a Fourth Amendment search. Although the officers received qualified immunity and the police department was not liable for damages, the constitutional holding provides important guidance for future investigations.

Together with the Supreme Court's earlier decision in Carpenter v. United States, 585 U.S. 296 (2018), these cases establish substantial constitutional protections for cellphone-location information.

The more difficult question concerns technologies that collect information ordinarily visible to anyone in public.

A Photograph of a Car Is a Different Case

License plate cameras present that question directly, and Virginia courts have already begun to answer it.

Companies such as Flock Safety install automated license plate recognition cameras that photograph passing vehicles and capture identifying information, including license plate numbers, colors, makes, models, and distinctive features. Police can later search those records to identify vehicles associated with criminal investigations.

A single camera records a vehicle at a particular location and time. Critics argue that large networks of cameras, combined with searchable databases, can allow police to reconstruct a person's movements without physically following the vehicle.

In April 2026, the Court of Appeals of Virginia rejected a Fourth Amendment challenge to Norfolk's Flock system in Robinson v. Commonwealth, 87 Va. App. 262, 927 S.E.2d 822 (2026).

Detectives investigating several commercial burglaries used the system to identify a white BMW SUV with distinctive black rims. Surveillance footage showed a similar vehicle near a location where someone attempted to redeem stolen lottery tickets. By searching Flock records, detectives identified the vehicle's license plate and connected it to the suspect.

The Court of Appeals held that the warrantless database search did not violate the Fourth Amendment. The court emphasized that license plates and vehicle characteristics are visible to the public and that Norfolk's system did not continuously track the defendant's movements.

The decision did not establish that every possible use of automated license plate readers is constitutional. Rather, the court examined the capabilities of the particular system and the circumstances of its use.

A related federal lawsuit reached a similar result.

In Schmidt v. City of Norfolk, 819 F. Supp. 3d 492 (E.D. Va. 2026), two Norfolk residents challenged the City's extensive Flock camera network, arguing that the collection and retention of vehicle information violated their Fourth Amendment rights.

In January 2026, the district court granted summary judgment for Norfolk. The court concluded that the system, as configured and operated, did not provide the comprehensive tracking of individuals' movements necessary to constitute a Fourth Amendment search.

The court also acknowledged that the constitutional analysis could change as camera networks expand and their capabilities improve. The plaintiffs appealed the decision to the Fourth Circuit.

For now, Robinson provides published Virginia appellate authority supporting the constitutionality of the particular warrantless ALPR search considered there. Schmidt provides additional support at the federal district court level, although the appeal remains unresolved.

When Surveillance Becomes Tracking

A more recent Virginia decision helps explain the constitutional distinction.

In Graves v. Commonwealth, 2026 Va. App. LEXIS 533 (Va. Ct. App. Oct. 6, 2026), a joint task force investigating suspected narcotics trafficking used a GPS device to monitor a truck traveling between Virginia and North Carolina.

Officers installed the device pursuant to a North Carolina warrant and tracked the vehicle for 24 days. The monitoring revealed a detailed record of the driver's movements, including repeated visits to particular locations.

The Court of Appeals held that the extended GPS monitoring constituted a Fourth Amendment search, even without an accompanying physical trespass.

Importantly, the court expressly distinguished Robinson. Norfolk's Flock cameras captured vehicles at particular locations and did not provide nearly continuous surveillance. The GPS device in Graves, by contrast, documented the vehicle's movements over an extended period, revealing information about the driver's habits and associations.

The court nevertheless upheld the search because the North Carolina warrant satisfied the Fourth Amendment's requirements. The court also concluded that Virginia officers participating in the joint investigation could rely on the out-of-state warrant.

The two decisions illustrate an important principle: The constitutional analysis depends not simply on whether police use technology, but on the nature, duration, and comprehensiveness of the surveillance.

Not Every Court Agrees About Flock Cameras

Although Virginia courts have upheld the systems considered in Robinson and Schmidt, courts elsewhere have begun reaching different conclusions about more extensive license plate databases.

In United States v. Kyle, 2026 U.S. Dist. LEXIS 225052 (N.D. Okla. Oct. 1, 2026), a federal district court in Oklahoma considered an officer's use of automated license plate reader databases during a traffic investigation.

The officer accessed systems containing historical vehicle-location records from multiple states. The databases supplied more than 50 records documenting the defendant's vehicle over approximately one month.

The court concluded that searching this extensive history intruded upon the defendant's reasonable expectation of privacy in the whole of her physical movements. Because the officer conducted the database search without a warrant or probable cause, and no applicable exception justified the search, the court suppressed the resulting evidence.

That ruling differs from the conclusions reached in the Norfolk cases. However, the systems and investigative circumstances were not identical. In particular, the Oklahoma officer accessed a broader collection of historical location information spanning multiple states.

The Oklahoma decision does not control Virginia courts, and the Fourth Circuit has not established a categorical rule governing every possible ALPR database search. Nevertheless, Kyle demonstrates that the constitutional treatment of these systems may depend heavily on the scope of the information available to investigators.

The distinction between a camera capturing a vehicle at one location and a database reconstructing weeks of travel is increasingly significant.

The Next Question: What Happens When Agencies Combine the Data?

Modern policing rarely depends on a single source of information.

Investigators may combine license plate records, residential surveillance footage, cellphone information, automated alerts, and conventional investigative methods to identify suspects and reconstruct events.

A recent Chesterfield County case illustrates the practical value of this approach.

In Adams v. Commonwealth, 2026 Va. App. LEXIS 552 (Va. Ct. App. Oct. 20, 2026) (unpublished), investigators examining a multiple-homicide case combined footage from residential security cameras with information obtained through Chesterfield County's Flock system.

The cameras helped identify a vehicle traveling near the crime scene before and after the murders. Investigators connected that information with DMV records, other surveillance footage, and additional evidence to obtain search warrants.

The Court of Appeals upheld the denial of the defendant's suppression motion. Although the case addressed probable cause for the subsequent warrants rather than the independent constitutionality of the Flock database search, it illustrates how different information sources can work together in a criminal investigation.

A separate Virginia decision demonstrates that these questions extend beyond cameras.

In Clements v. Commonwealth, 88 Va. App. 511, 933 S.E.2d 488 (2026), Arlington County investigators obtained a reverse-keyword search warrant requiring Google to identify accounts that searched for a particular residential address during a specified time period.

Unlike a traditional warrant directed at an identified suspect's information, a reverse-keyword warrant begins with a search term and seeks to identify otherwise unknown users who entered it.

The Court of Appeals affirmed the conviction under the good-faith exception to the exclusionary rule without deciding whether the warrant was constitutionally valid. Judge Chaney, concurring in the judgment, concluded that the warrant lacked sufficient particularized probable cause, although she agreed that suppression was unwarranted.

The majority expressly left the underlying constitutional question unresolved.

Together, Adams and Clements illustrate both the investigative value and the constitutional complexity of technologies that identify individuals by searching large collections of previously gathered information.

The government may lawfully possess or obtain individual pieces of information. Whether combining those records into a comprehensive account of someone's movements or activities creates a Fourth Amendment search remains an evolving question.

Virginia Already Wrote Rules for License Plate Cameras

While courts continue to evaluate the constitutional limits of automated surveillance, Virginia has established statutory restrictions on law enforcement use of license plate recognition systems.

Virginia Code § 2.2-5517 regulates how law enforcement agencies may use these systems, retain information, share records, and respond to automated notifications.

The statute limits authorized uses to specified law enforcement purposes. Agencies may query the systems during criminal investigations supported by reasonable suspicion that a crime occurred. They may also use the technology in certain investigations involving missing or endangered persons and human trafficking, and to receive designated alerts involving those individuals, outstanding warrants, stolen vehicles, or stolen license plates.

The law also imposes important restrictions on retaining and sharing information.

System data generally must be deleted 21 days after capture. Audit-trail data generally must be deleted after two years. Information connected with ongoing investigations, prosecutions, or civil actions must be preserved as the statute requires.

Agencies cannot sell system data or audit-trail data, and they generally cannot share the information with outside databases. The statute permits limited disclosures, however, including sharing with other law enforcement agencies for authorized purposes, complying with court orders, and meeting specified discovery obligations.

An automated notification also does not, standing alone, establish reasonable suspicion sufficient to stop a vehicle. Before making a stop based on a notification, an officer must develop independent reasonable suspicion or confirm that the license plate or identifying characteristics match the information that generated the notification.

Agencies must maintain written policies governing authorized uses, employee training, data security, retention, audits, and information sharing. They must also conduct internal audits at least every 30 days and comply with applicable reporting and public-posting requirements.

Willful and intentional misuse of the system or prohibited disclosure of information can constitute a Class 1 misdemeanor. Evidence obtained through violations of certain statutory provisions is inadmissible when offered by the Commonwealth in criminal or civil proceedings.

These protections operate independently of the constitutional analysis. Even when a particular database search does not implicate the Fourth Amendment, the agency must still comply with Virginia law.

What to Do With the Tools You Already Have

For Virginia law enforcement agencies, the recent decisions suggest three practical steps.

First, treat cellphone and GPS location tracking as constitutionally protected investigative methods. The decisions in Carpenter, Chatrie, Andrews, and Graves establish substantial Fourth Amendment protections for location information and prolonged electronic tracking. Agencies should generally obtain warrants supported by probable cause before conducting these searches unless a recognized exception applies.

Second, operate license plate recognition systems within Virginia's statutory requirements. Agencies should incorporate authorized-use restrictions, retention periods, auditing procedures, and information-sharing limitations into their written policies and vendor agreements. The favorable decisions in Robinson and Schmidt do not eliminate those obligations.

Third, consider what surveillance technologies can accomplish together. Agencies should not assume that the constitutionality of collecting individual observations necessarily resolves the constitutional implications of assembling those observations into a detailed record of someone's activities. The greater the scope and precision of the information available, the more carefully agencies should assess their legal authority.

These considerations also extend beyond police departments. Local governments, school divisions, and public employers increasingly use security cameras, parking systems, access controls, badge records, and other technologies that create searchable records of individual activity. Some private entities are also giving public entities access to their cameras.

Although Virginia's ALPR statute does not necessarily govern those systems, public agencies should consider the privacy implications of collecting and combining information about individuals.

None of this means modern surveillance technologies are inherently unlawful. Properly used, they can help locate an abducted child, identify a shooting location, apprehend a dangerous suspect, establish an alibi, or clear an innocent person. The law permits those important public-safety benefits while imposing limits on how the government collects, retains, and uses information.

The Fourth Amendment has long regulated the government's authority to conduct searches. Modern technology now requires courts to consider not only what the government observes, but also what it can learn by collecting, combining, and analyzing those observations.

As surveillance systems become more sophisticated, the distinction between observing an event and reconstructing a person's movements will become increasingly important.

Anne Lahren is a Pender & Coward attorney focusing her practice on civil litigation, immigration, labor and employment and family law.

Jeff Willson is a Pender & Coward labor and employment attorney, who has advised public and private employers for more than twenty years, helping them navigate the legal, operational, and reputational risks that arise in managing today’s workforce.