Minneapolis recently dramatically limited the amount of time it holds on to license plate tracking data, but St. Paul has moved in the other direction. Now the cities keep the data for the same period: 90 days.

How long agencies hold onto data from license plate readers has become a hot-button issue in law enforcement circles, and is the subject of an ongoing state-level discussion about possible legislative limits.

St. Paul cops are retaining the public location data on vehicles in the area for 90 days, after initially storing it for only 14. The change was spotted by Public Record Media, an organization that frequently files open records requests and posts the documents online. The policy was revised on Oct. 29.

Sgt. Paul Paulos, a spokesman for the department, said the change was made because of potential criminal investigations.

"If there's a crime that is reported ...investigators have an additional tool to go back and look at what cars were in the area potentially that day, and so forth, so that can be used in the investigation," Paulos said.

The change is notable because the timeline increased, rather than decreased. Minneapolis' recent change limited the retention times to 90 days from one year, partly out of concern about the public nature of the data.

Paulos confirmed that 90 days represents the time when data is now deleted absent an investigation. But the policy has confusing phrasing. It says data must be retained "for a minimum of 90 days at the end of which time they are no longer retained."

See the two versions of the policy below: