Elements of a sound policy for automated license plate readers


The Daily Chronicle covered the October 11 city council discussion that led to approval of the purchase of 12 automated license plate readers. The newspaper purports to know how DeKalb PD plans to use the ALPRs, but that is not entirely true. They talked about some aspects, but as yet DeKalb has no formal policy on usage, and until a written policy is put into place PD has no local rules for the technology — and no regulations exist at our state and federal levels, either.

That being said, we might reasonably expect a policy is forthcoming, just as the policy for body-worn cameras was introduced last year. Also, more than a dozen states do have ALPR regulations targeting privacy concerns, which can act as a guide in addressing the issues inherent to the technology. Here’s a summary of decisions I suggest need to be made and spelled out for the public:

  • Data access rules for who, how, and when (i.e., public logging, time limits for access.).
  • Time limits for data storage and destruction.
  • Prohibition on selling data and strict limits on sharing it.
  • Confidentiality and Freedom of Information compliance.
  • Enactment of third-party audit processes to assist in oversight.

All of these decisions are important, and to me, two of them are critical to privacy and prevention of abuse of the technology: data access and storage limits. If we time-limit storage, we reduce the risk that ALPRs replace GPS surveillance. Here’s why that’s desirable:

It wasn’t so long ago that privacy rights advocates were cheering a Supreme Court decision in United States v. Jones that put limits on law enforcement’s ability to place GPS trackers on cars. With enough license-plate readers on the street, all feeding into a centralized database, the government could forgo GPS trackers and the Fourth Amendment tests that they trigger, and just monitor all cars always, plugging in a license plate when they want to know about the bygone movements of a particular person.

~ The Atlantic, “Total Information Awareness: ‘Scanning License Plates’ Edition”

As for the benefits of limited access, we can at least put protections into place to help prevent use of ALPR data for political and other private reasons, and that probably means granting access only to sworn police officers for narrowly-defined purposes.

The city conceivably could end up with a policy that reasonably balances the needs of local law enforcement with the rights of citizens, an outcome to strive for and a good first step. But it wouldn’t cover law enforcement in other Illinois municipalities, nor would it apply to private business. We should see protective legislation passed at the state level, too. Unfortunately, that doesn’t appear to be happening soon; so if you care about ALPR policy in DeKalb, please pass it on to your representatives on the city council.


Chicago Sun-Times: “Use license plate readers to solve crimes, not to snoop.” (Recent)

Electronic Frontier Foundation: “Street-level surveillance: automated license plate readers (ALPRs)”