Analyzing ALPR data is an imperfect science, and we intend to update this dataset as inconsistencies are identified. If you encounter an issue, please email Dave Maass at dm@eff.org

The reason for these imperfections is that the law enforcement agencies we surveyed sometimes appeared not to fully understand how their systems worked and consequently provided inaccurate, incomplete, or unclear data. When the problem was obvious, we contacted the agency to obtain more precise information. However, it is possible that incorrect data provided by agencies may appear in the data set due to agency error.

Further, law enforcement agencies sometimes provided documents that were difficult to read or interpret, creating a greater potential for human error during the manual data entry into our dataset. Again, we intend to update the datasets as these issues are identified.

Consequently, this data is intended to give a broad overview of the ALPR data flowing across the country. For specific entities, we recommend users inspect the primary documents linked in the dataset. If you have further questions about the source document, they should be directed to the agency that produced the record.

To our knowledge, there is only one entity capable of disclosing a comprehensive dataset that would near perfect accuracy: Vigilant Solutions itself. We urge the company to publish this data, which would not only save our time, but also the time of every law enforcement agency staff member who must process our public records request.