Sixteen States and DC File Fourth Circuit Brief in Support of Norfolk's Surveillance

In Schmidt v. Norfolk, the District Court for Virginia’s Eastern District found that the City of Norfolk’s use of Flock LPR cameras to track plaintiffs within the city of Norfolk did not violate the US Constitution. The Institute for Justice appealed. Sixteen states^[1] and the District of Columbia have now filed an amicus curiae brief conceding a number of critical anti-surveillance points.

For the most part, the brief follows Flock’s primary argumentative strategy: if a single observation in public is legal, then all observations in public must be legal. It is a simplistic argument that falls apart under any scrutiny — after all, crimes like stalking and harassment exist. It’s legal to follow a car on the highway, but that doesn’t automatically mean it’s legal to follow your ex’s car to the office, soccer practice, and their therapy appointments.

There’s misdirected effort here, too. The brief’s first argument — pages 6 through 11 — labors to prove that a driver has no privacy interest in a license plate sitting in plain view. No one said otherwise. The plaintiffs concede the point, and the brief quotes the concession on page 12: they “don’t challenge the isolated use of ALPRs for capturing license plate numbers,” only Norfolk’s aggregated, city-wide use.

The fact that Flock has created a nationwide database is barely discussed. That is not so much an omission in the brief, but a result of the plaintiff barely raising it in the petition. The Institute for Justice’s case in San Jose, CA, takes a similar approach. The Supreme Court places weight on the scope of the tracking; it’s a test that might be easier to satisfy with the nationwide network, but the IJ rightly argues even a city-wide network exceeds the Constitution’s limits.

Regardless, the amici states raise the nationwide network. The article cited in the brief’s third footnote is even headlined “For the Most Part, We Can Track You All Over the Country.” That piece is generally critical of LPR deployments in South Carolina, and, beyond its headline, contains lines like “[Flock] does not explain how the data is deleted.” and “Merely by driving a car with a license plate, people are often unwittingly entered into massive databases that are then shared, Bowers said.”

But the nationwide network is not the only point the “one scan is legal” argument glosses over. Another point the brief references in a citation but skips is the one made in Beautiful Struggle: that of data retention. The brief concedes 21-days of data retention, the maximum under Virginia law^[2]. To understand why this is so relevant, we have to look at the states’ and Flock’s talking point, lifted from Carpenter, about “the whole of an individual’s movements.”

In Carpenter, which was about cell phone (“CSLI”) records, the Supreme Court looked at how much information could be obtained from cell phone records and found that it was the whole of a person’s movements. The District Court in Schmidt found that tracking by ALPR didn’t go quite as far as cell phone or ankle monitor tracking would have, and therefore it did not meet that definition.

But that ignores Leaders of a Beautiful Struggle v. Baltimore Police Department, a case the states do cite in their brief, where the court held that because of the 45 day retention, BPD created a “detailed, encyclopedic” record of movements (emphasis added):

Carpenter applies squarely to this case. More like the CSLI in Carpenter and GPS-data in Jones than the radio-beeper in Knotts, the AIR program “tracks every movement” of every person outside in Baltimore. Because the data is retained for 45 days—at least—it is a “detailed, encyclopedic,” record of where everyone came and went within the city during daylight hours over the prior month-and-a-half. … AIR data is more like “attach[ing] an ankle monitor” to every person in the city. “Whoever the suspect turns out to be,” they have “effectively been tailed” for the prior six weeks. (“[P]olice need not even know in advance whether they want to follow a particular individual, or when.”). Thus, the “retrospective quality of the data” enables police to “retrace a person’s whereabouts,” granting access to otherwise “unknowable” information.^[3]

We do not suggest that the AIR program allows perfect tracking of all individuals it captures across all the time it covers. … Still, the program enables photographic, retrospective location tracking in multi-hour blocks, often over consecutive days, with a month and a half of daytimes for analysts to work with. That is enough to yield “a wealth of detail,” greater than the sum of the individual trips. It enables deductions about “what a person does repeatedly, what he does not do, and what he does ensemble,” which “reveal[s] more about a person than does any individual trip viewed in isolation.” Carpenter held those deductions go to the privacies of life, the epitome of information expected to be beyond the warrantless reach of the government. And here, as there, the government can deduce such information only because it recorded everyone’s movements.

— Leaders of a Beautiful Struggle v. Baltimore Police Dep’t, 2 F.4th 330, 341–42 (4th Cir. 2021)

The Carpenter Court found seven days sufficient history to bring it into the territory of a constitutional search: “It is sufficient for our purposes today to hold that accessing seven days of CSLI constitutes a Fourth Amendment search …”. Beautiful Struggle said 45 days, even without perfect tracking of individuals, was sufficient, and that the picture was “greater than the sum of the individual trips”. Norfolk’s tracking of individual trips over multiple weeks and the 21 day retention period falls neatly in between Carpenter and Beautiful Struggle.^[4] The District Court’s finding that this would not be a search is plainly the outlier in the series.

The brief also contains an interesting technical wrinkle: its citation of United States v. Chatrie, 107 F.4th 319 (4th Cir. 2024). That’s a citation to the panel opinion, which was vacated in November of 2024, when the 4th Circuit (where this brief was filed) granted an en banc rehearing. The proposition they cited the case for (that geofence searches are not “searches” under the Fourth Amendment) does not exist in the April 2025 en banc opinion at all.

Even worse for the states and their brief, that en banc opinion in Chatrie was vacated by the Supreme Court today (June 29, 2026). Chatrie is a cell-phone case, so it does not decide the ALPR question directly but the reasoning leaves the states no room. The Court held:

Police officers conducted a Fourth Amendment search when they acquired Chatrie’s location data from Google because an individual has a reasonable expectation of privacy in his cell-phone location information.

And, in the line that lands hardest on this brief’s “it’s only a few data points” arithmetic:

… this Court has never understood Fourth Amendment protections as kicking in only once an intrusion “goes too far” … Where the Fourth Amendment applies, it applies regardless of “the quality or quantity of information” the government obtains. That approach makes all the more sense when, as with Location History, law enforcement officials can select the time-limited set of materials they want from an all-encompassing database.

The brief also cites Knotts^[5] throughout — this is a 1983 case which directly undercuts the brief’s main argument. The quote given is “A person travelling in an automobile on public thoroughfares has no reasonable expectation of privacy in his movements from one place to another.” The more relevant quote from the next paragraph is omitted:

Respondent does not actually quarrel with this analysis, though he expresses the generalized view that the result of the holding sought by the government would be that “twenty-four hour surveillance of any citizen of this country will be possible, without judicial knowledge or supervision.” But the fact is that the “reality hardly suggests abuse,” Zurcher v. Stanford Daily; if such dragnet type law enforcement practices as respondent envisions should eventually occur, there will be time enough then to determine whether different constitutional principles may be applicable. Insofar as respondent’s complaint appears to be simply that scientific devices such as the beeper enabled the police to be more effective in detecting crime, it simply has no constitutional foundation. We have never equated police efficiency with unconstitutionality, and we decline to do so now.

The Court found that the existence of tracking technology did not violate the Constitution — and it expressly reserved the question of whether deploying that technology as a “dragnet” would.

The efficiency line is interesting, because the states argue it backwards here. In Knotts, it was the defendant who argued that efficient, technology-driven surveillance was unconstitutional. The Court turned that down flat: it has “never equated police efficiency with unconstitutionality.” Efficiency isn’t the test. The states now run the mirror image — uphold our surveillance because it works — and Knotts disposes of that just as fast. Effectiveness doesn’t decide the question in either direction.

The states’ strongest appellate authority has its own fit problem. They lean on United States v. Gregory, an Eleventh Circuit case, for the idea that automatic, nonstop cameras raise no Fourth Amendment concern. But Gregory is a pole-camera case: fixed cameras pointed at the outside of one house during a drug investigation. Trying to apply it to the 176-camera grid wired into a nationwide database asks a case about a single stationary camera to answer the dragnet question Knotts left open.

The Gregory panel wasn’t even fully sold — a concurring judge cautioned against assuming the public-view doctrine “immunizes pole cameras regardless of the length of time they record,” and noted that the Eleventh Circuit’s parallel reasoning about cell-site data was exactly what the Supreme Court threw out in Carpenter.

The Justices rejected that efficiency rationale head-on, in another case the states cite:

We cannot deny that our decision today will have an impact on the ability of law enforcement to combat crime. Cell phones have become important tools in facilitating coordination and communication among members of criminal enterprises, and can provide valuable incriminating information about dangerous criminals. Privacy comes at a cost. … Our cases have historically recognized that the warrant requirement is “an important working part of our machinery of government,” not merely “an inconvenience to be somehow ‘weighed’ against the claims of police efficiency.” Coolidge v. New Hampshire, 403 U.S. 443, 481, 91 S.Ct. 2022, 29 L.Ed.2d 564 (1971).

In all, the states’ two arguments are: (1) a single capture is legal, therefore all captures are legal; and (2) Flock’s LPR network makes police more “efficient.”

Neither argument actively engages with the facts of the case, which are about a city-wide mass surveillance dragnet with long-term historic data collection and warrantless searches of that data. If these are the best arguments the Attorneys General for sixteen states and DC can muster, and with the Chatrie decision in the bank, Schmidt may continue to be an interesting case.