What data do license plate readers collect?

Every read stores at least a plate number, a photo, the date and time, and the location. Many systems add make, model, color and distinguishing marks. On its own that's one data point. Stored and searched over time, it becomes a record of where a car has been.

Updated November 5, 2026 · Sources linked below

What's in a single read

• Plate number, plus the state and plate type on some systems.
• Date, time and GPS location of the camera.
• One or more photos of the vehicle, which can show the driver, passengers and surroundings.
• Vehicle attributes on newer systems: make, model, color, damage, bumper stickers (sometimes called a "vehicle fingerprint").

Sources: EFF; NCSL; Flock agreement. Reads generally don't include the owner's name, but agencies can look that up in other databases (EFF).

Fixed, mobile and trailer readers

Fixed cameras sit on poles, traffic signals, overpasses and at town entrances. Mobile readers ride on patrol cars and can sweep parking lots. Trailers can be towed and left in place (EFF). Private repossession fleets also collect plate reads and sell access (EFF). Our map covers only fixed cameras that volunteers have mapped: 144,253 of them. Mobile readers can show up anywhere.

What happens to the data

Hot lists: each read is checked against lists of plates of interest, such as stolen cars, warrants, AMBER alerts or plates an officer adds, and a match triggers an alert. History: reads are stored so investigators can search a plate, a partial plate or a location later (EFF, NCSL). State transportation agencies also use ALPRs for traffic analysis, and HOAs and businesses run their own (NCSL).

How long states let agencies keep it

As of September 2026, at least 28 states have statutes that expressly address ALPRs, and at least 19 set retention limits (NCSL). Examples:

Summarized from NCSL. Exceptions for active investigations, warrants and preservation requests apply. Read each statute, and see your state page. This isn't legal advice.

Misreads and wrongful stops

ALPRs misread plates. EFF documents a 2009 San Francisco stop in which a woman was held at gunpoint after a reader misidentified her car as stolen. The case led the Ninth Circuit to rule that the technology alone can't justify such a stop (EFF). Kentucky and Oregon now require officers to visually confirm a match before stopping a car (NCSL).

What courts have said

The Supreme Court held in United States v. Jones (2012) that attaching a GPS tracker to a car and monitoring it is a search (Oyez). In Carpenter v. United States (2018) it held that police generally need a warrant to get historical cell-phone location records (Oyez). How those rulings apply to plate-reader databases is still being argued in lower courts. EFF tracks several of the cases (EFF).

Can you see the data about your car?

Often not. At least 12 states exempt ALPR data from public-records requests (NCSL). But agency policies, contracts, sharing lists and audit reports are usually requestable, and some states require public policies or annual reports. Florida allows disclosure to the person a plate is registered to in some cases (NCSL). Use our request template.