St. Louis Mayor Lyda Krewson and the city’s interim police chief have called for a third-party investigation into the department’s handling of protests over the last two weeks.

They have pledged an investigation into complaints, but called on the U.S. attorney to conduct an independent probe, the St. Louis Post-Dispatch reports.

The department’s Internal Affairs Division has received a dozen complaints, a filmmaker couple and the ACLU of Missouri have sued over a controversial mass arrest on Sept. 17, and the Post-Dispatch has complained to the department about the arrest of a journalist covering the protests.

Protesters took to the streets when a judge found former police officer Jason Stockley not guilty of first-degree murder in the on-duty shooting death of Anthony Lamar Smith.