The U.S. Justice Department said on Monday it will investigate Chicago¡¯s police department following protests over the 2014 police shooting death of a black teenager, on the same day local prosecutors said they would not seek charges in another police shooting case.

U.S. authorities will look at the department¡¯s use of force, including deadly force, among other issues, U.S. Attorney General Loretta Lynch said at a news briefing.

¡°Our goal in this investigation ... is not to focus on individuals but to improve systems,¡± the United States¡¯ top law enforcement official said.