ST. PAUL — State lawmakers are gearing up to debate again whether to adopt rules limiting how police can use automated license plate readers.

The tiny cameras, which are usually mounted on squad cars, scan license plates and check them against a database of wanted vehicles. But for two years, law enforcement and privacy advocates haven’t been able to agree on how long the data can be kept.

A legislative panel set the stage on Monday for how the issue will play out in 2015 by passing recommendations to the full Legislature that would prevent police from keeping any data that’s not connected to an investigation or wanted person. Any license plate that doesn’t result in a “hit” would have to be tossed.

“I firmly believe that if you’re innocent, there is no reason for law enforcement … to be keeping information on you,” said Rep. John Lesch, a St. Paul Democrat.

But the law enforcement agencies that use them — mostly in urban areas like the Twin Cities, Rochester and Duluth — won’t cede ground on the issue.