U.S. Senator Bernie Sanders is joining those who are calling for the U.S. Justice Department to investigate the Chicago Police Department.

The calls come in response to the release of dash cam footage showing a white police officer fatally shooting a 17-year-old Black male in Oct. 2014.

“I join with those calling for a federal investigation into the practices of the Chicago Police Department. Furthermore, any official who helped suppress the videotape of Laquan McDonald’s murder should be held accountable,” Sanders said in a statement. “And any elected official with knowledge that the tape was being suppressed or improperly withheld should resign. No one should be shielded by power of position.”

The release of video footage detailing the circumstances of McDonald’s death incited mass protests in the city. Earlier this week, Mayor Rahm Emanuel fired Chicago Police Superintendent Garry McCarthy. Activists and community leaders are now calling for him to step down.