Briscoe and Green are working the phones at their desks, and the soda can on Lenny's desk changes orientation.
A special grand jury cannot be convened by the District Attorney's office, they are only able to be convened by the United State's Attorney's office to investigate possible organized crime cases and to bring charges against said criminal organization in federal court if one is found to be in existence.
The victim's body is shown being loaded into an ambulance by paramedics. However since the victim was already dead on arrival the body would be picked up and transported by a van from the corners office, not by an ambulance.