After announcing the indictment of one current Chicago police officer and two former officers for their purported roles in the alleged cover-up into the circumstances surrounding the shooting of Laquan McDonald, special prosecutor Patricia Brown Holmes declined to say if more were coming.Holmes at a news conference Tuesday repeatedly emphasized that her investigation into the alleged police cover-up of the Oct. 20, 2014, shooting of McDonald is still open.Both Holmes’ statements Tuesday and the indictment issued by a …