Midway through the season (Episode 8), Antonio leaves the Intelligence Unit to join the State’s Attorney’s office as a chief investigator, a move designed to lead into the spin-off Chicago Justice .
In the season finale, Lindsay resigns from the Chicago Police Department to accept a position with the FBI in New York after being investigated for her conduct during an assault on a suspect. Off-screen, Bush cited abusive behavior and harsh working conditions as her reasons for leaving. Chicago P.D. - Season 4
The season's narrative is framed by accountability and the personal cost of life in the Intelligence Unit: Midway through the season (Episode 8), Antonio leaves
Season 4 marked the end of an era for two of the show's original leads and introduced a future mainstay: The season's narrative is framed by accountability and
In a devastating multi-episode arc, Alvin Olinsky (Elias Koteas) loses his daughter, Lexi, in a warehouse fire, pushing him to a grief-stricken breaking point.
In "All Cylinders Firing," Desk Sergeant Trudy Platt (Amy Morton) is brutally attacked outside her father's home, leading to a personal and harrowing investigation into her past.