July 17, 2013

Documents obtained from Colorado police departments show tracking data is kept for years, even indefinitely

Denver – Police departments in Colorado and all around the country are rapidly expanding their use of automatic license plate readers to track the location of drivers, but few have meaningful rules in place to protect privacy rights, according to documents released today by the American Civil Liberties Union. As a result, the new documents reveal, many departments are keeping innocent people’s location information stored for years or even indefinitely, regardless of whether there is any suspicion of a crime.

“License plate scanners can be a legitimate tool for law enforcement when their use is narrowly tailored and focused on an ongoing criminal investigation,” said ACLU of Colorado Public Policy Director Denise Maes, “but these documents show that police departments around the state are using license plate scanners to conduct broad, invasive surveillance of all citizens in case they might someday commit a crime.”

In Colorado, grants from the Colorado Auto Theft Prevention Authority (CAPTA) directly or indirectly funded the purchase of automated license readers in Boulder, Longmont, Lafayette, Erie, Louisville, Commerce City, and Thornton. The Adams County Sheriff’s Office also received funding from CAPTA for automated license plate reader equipment.

The systems use cameras mounted on patrol cars or on objects like road signs and bridges, and the documents show that their deployment is increasing rapidly. They photograph every license plate they encounter, use software to read the number and add a time and location stamp, then record the information in a database. Police are alerted when numbers match lists containing license numbers of interest, such as stolen cars.

View an interactive slideshow on automated license plate readers

Last summer, the ACLU of Colorado joined affiliates in 37 states to file nearly 600 freedom of information requests asking federal, state, and local agencies how they use the readers. The 26,000 pages of documents produced by the agencies that responded – about half – include training materials, internal memos, and policy statements. The results and analysis are detailed in an ACLU report released today called “You Are Being Tracked,” which includes charts and policy recommendations.

The study found that not only are license plate scanners widely deployed, but few police departments place any substantial restrictions on how they can be used. A tiny fraction of the license plate scans are flagged as “hits.” For example, in Maryland, for every million plates read, only 47 (0.005 percent) were potentially associated with a stolen car or a person wanted for a serious crime. Yet, the documents show that many police departments are storing – for long periods of time – huge numbers of records on scanned plates that do not return hits.

In Colorado, for example, Commerce City and Aurora keep all driver location data from automated license readers for two years. In Aurora, some scans are then transferred to a database for indefinite retention.

The City of Longmont maintains all automated license reader data for a minimum of one year and a maximum of two. Longmont license plate readers do not distinguish between Colorado and out-of-state plates, occasionally resulting in false hits for innocent drivers.

“Without sufficient privacy protections, we could quickly reach a point where these devices are in operation on every block, monitoring like a GPS tracker every movement we make, including what friends, doctors, protests, political events, or churches we visit,” added Maes.

The ACLU report contains over a dozen specific recommendations for government use of license plate scanner systems, including: police must have reasonable suspicion that a crime has occurred before examining the data; unless there are legitimate reasons to retain records, they should be deleted within days or weeks at most; and, people should be able to find out if their cars’ location history is in a law enforcement database.

The report, an interactive map with links to the documents, and an interactive slide show are available at: www.aclu.org/alpr