Storing ALPR data by law enforcement deemed illegal

An interesting decision was passed by a Fairfax County judge on the use of ALPR/ANPR cameras by the local law enforcement agency. It is not a landmark case because it is based on the State law called Data Act or Virginia’s Government Data Collection and Dissemination Practices Act. It is unlikely to apply in other jurisdictions, but it does help to form a framework around a controversial technology.

Fairfax County Police cars have ALPR/ANPR cameras mounted on the vehicles. The cameras are processing the license plates in real time and alert the officers if there are matches against the “hot list” of suspect or stolen cars. The judge had no problem with that.

The entire list of read plates is then stored in a central database along with the time, location and other metadata from the capture for 364 days. Again, there is nothing illegal in that because the license plate is not “personal information”. The controversial part is in the ability of the law enforcement personnel to match the plate to an individual.

While the Court deduces the ALPR record-keeping process does not itself gather or directly connect to “identifying particulars” of a vehicle owner, the ALPR system does enable police officers to cross-reference ALPR data with the identity of an individual. In other words, access to the license plate number stored in the ALPR system “permit[s] connection” to the identity of the vehicle’s owner with a few clicks on the screen, all from the driver’s seat of a police cruiser.

Robert J. Smith,
Judge, Fairfax County Circuit Court

Storing automatically collected license plate data is NOT OK if you have the means of linking it to the individual

  • Automatic collection of license plate data – OK
  • Matching data in real time for law enforcement purposes – OK
  • Storing data for “future use” – NOT OK if you can match it to the individual


The case came about after a Fairfax resident submitted a Freedom of Information Request to the local police department asking for details on his number plate. They complied. It turned out that it was possible to request data on any plate. So you could outsource your stalking to the local police force. Initially, the case was dismissed, then overturned on appeal and now resulted in the injunction to stop the “passive use” of ALPR/ANPR data by the police.

The case was reported by major news outlets and supported by civil liberty groups.


* – feature image by William Warby via Flickr