Rockville acts to limit license-plate reader data retention

Rockville’s Mayor and Council voted unanimously last night to limit the retention of data from automatic license-plate readers, a big win for the privacy of Rockville residents.

Automatic license-plate readers are cameras (usually mounted to police cars) that scan, translate, and record license plate numbers, along with the time and location of the scan.  The City of Rockville owns three of these cameras.  They are a terrific police tool, but what to do with the data once it is collected has been a thorny issue.  The data is quite useful at the moment it is scanned (is the car that just passed by wanted?), but the usefulness of the data to police drops off drastically over time.  The City of Rockville had been sending the data to the Montgomery County Police Department, which has a policy of keeping it online for a year and archiving it permanently.

I raised concerns about this practice, noting that Montgomery County is an outlier – most police departments in the state keep their data for a year at most, and it is almost unheard of to keep this sort of data forever.  There is no similar data that police departments collect on people who are under no suspicion whatsoever.  A growing archive of this data, along with an expanding fleet of cameras, would over time amount to a permanent, lifelong detailed record of everyone’s activities.  There is no reason for a government to have that kind of information on its people.

Rockville Police Chief Terry Treschuk recommended that the City of Rockville change its policy and send our ALPR data directly to the State of Maryland’s fusion center, which keeps the data for a year and then deletes it.  The Montgomery County Police Department still has full access to the data when it needs it.  This strikes an excellent balance between the legitimate police use of this terrific tool and the legitimate right that ordinary people have in the privacy of their whereabouts.

Thanks very much to Chief Treschuk, who took my concerns seriously (even though he and I agreed that we were coming at this issue from two different directions) and crafted this change in policy.  Thanks to City Manager Barb Matthews, who coordinated the staff’s response. Thanks also to those who so ably illuminated the issues for the worksession we held on this: Cpl. Ken Matney of the Rockville City Police Department; Russ Hamill, assistant chief of the Montgomery County Police Department; Ginger McCall, open government director of the Electronic Privacy Information Center; and David Rocah, staff attorney at the American Civil Liberties Union of Maryland.

And thank you, of course, to my colleagues for listening and acting.

It is not often that local government can act to protect the privacy of its people; usually, all the relevant policies are being decided at other levels of government.  But the City of Rockville did what it could last night.  It is a small but significant step in the right direction.