Texas Attorney General Ken Paxton has launched an investigation into the Dallas Police Department’s immigration policies, less than a month after Interim Police Chief Michael Igo faced criticism from prominent conservatives.

Texas Attorney General Ken Paxton says he’s opened an investigation into the city of Dallas alleging the police department is refusing to comply with state and federal immigration laws. The attorney general released a statement Thursday saying interim Dallas Chief of Police Michael Igo said “The Dallas Police Department is not assisting any federal agency on detaining people that are either documented or undocumented in the City of Dallas.