Flock cameras have learned to identify cars without license plates

Flock Safety, the maker of automated license plate recognition (ALPR) cameras, has technology that can identify vehicles even without reading a plate. This is revealed in a 2024 company presentation described on Bruce Schneier's blog.

According to the document, law enforcement officers can access data on stickers, decorative features, luggage racks on the front and top of a vehicle, as well as on temporary and unique regional license plates. Flock calls this feature “Vehicle Fingerprint.”

The presentation frames the technology as a way to obtain additional information about a vehicle “even in the absence of complete license plate data.” According to the company, this allows police to “build stronger cases with less starting information.”

Beyond identifying individual cars by their outward features, the system makes it possible to search for groups of vehicles that investigators believe are traveling together. For this there is a “multi geo search” feature — searching across several geographic points at once.

Thus Flock cameras are able not only to capture license plates but also to accumulate a broader body of visual data about vehicles, which expands the ability to track cars even in cases where the plate is hidden, damaged or missing.

Such features once again raise questions about the scale of the video surveillance provided by the Flock camera networks installed in many U.S. cities, and about how much data on the movements of private individuals becomes available to law enforcement without any direct link to a license plate.

Source: Schneier on Security