ST PAUL, Minn. — The Minnesota chapter of the American Civil Liberties Union sued the city of St. Paul on Wednesday, saying the police department has improperly withheld public data about its policing activities in the community.

The lawsuit says that although Mayor Melvin Carter and police Chief Todd Axtell have publicly committed to transparency and accountability, the St. Paul Police Department has not provided public data as required by law. The ACLU is seeking information about every traffic stop, citation, arrest and use of force by St. Paul police since 2015.

The group says it has been waiting for the data for 18 months. ACLU staff attorney David McKinney said police have provided only a fraction of the data requested, and that the information is clearly public under state law.

City Attorney Lyndsey Olson said in a statement to the St. Paul Pioneer Press that the administration supports the work of the ACLU and has directed the police department to provide the data as soon as possible.

In December 2016, the department publicly released traffic stop data it had collected for 15 years. The initial data showed officers routinely stopped, searched and ticketed black drivers at higher rates than white drivers. McKinney said that data made the ACLU want to learn more.

“A full accounting of police activities is crucial to ensure adequate oversight, accountability and transparency, and to understand the scope of racial disparities that are already apparent in the limited amount of data that the police department has released. This information is essential to make sure that all interactions with police are safe and just," McKinney said.

According to the lawsuit, the police department doesn't track investigative stops, even though its manual requires officers to record such stops. The department has said its electronic storage system is “antiquated" and doesn't allow for saving an electronic report. But the ACLU says the system can produce detailed arrest data to the Bureau of Criminal Apprehension, and says the department is required under law to keep records that are easily accessible for convenient use.