Police in Minnesota would have to make detailed disclosures about how they use license plate tracking technology under a bill introduced Monday at the Legislature.

The legislation, introduced by Sen. Scott Dibble, DFL-Minneapolis, requires law enforcement to keep a public log of where they use license plate readers, when they collect data, and how much data they collect.

License plate readers are small scanners, often mounted on squad cars, that check every license plate they see against a database of wanted vehicles. But they also store location information on non-criminals.

Dibble's bill, which is expected to mirror House legislation sponsored by Rep. Mary Liz Holberg, would require law enforcement to delete data on non-criminals immediately.

Cops could store the information if it relates to "an active criminal investigation or other preexisting law enforcement or correctional proceeding, sanction or supervision."

Law enforcement lobbyists, such as the Minnesota Chiefs of Police Association, are likely to push back hard against the Dibble-Holberg effort. Police have argued that storing data on non-criminals for some period is valuable, since suspects can take weeks to materialize in a criminal investigation.

Minneapolis cops say that the location of their stationary cameras (such as the one pictured) are not public under the "security information" clause of the state's open records law. They redact those locations when responding to open records requests.

Here is the exact data the bill would require police to store in a public log:

(1) locations at which the reader is installed or used;
(2) specific times of day that the reader actively collected data; and
(3) the aggregate number of vehicles or license plates on which data are collected for each period of active use.