A senator's political rally turns into tragedy when a man begins shooting, which leaves the senator and six other attendees dead. As Detectives Morales and Jaruszalski use the department's latest tech toy to find the killer, DDAs Dekker and Rubirosa butt heads over the best way to run the case. Elsewhere, TJ's mission to locate Winters' killer puts him at risk.

Cast: Alfred Molina, Corey Stoll, Rachel Ticotin, Alana De La Garza, Terrence Howard, Shawn Hatosy, Currie Graham, Teri Polo, Robin Weigert, Tamlyn Tomita, Henri Lubatti, Scott Lawrence, Rich Hutchman, B.K. Cannon, Barry W. Levy