When Chicago P.D. first premiered in 2014 as part of Dick Wolf’s One Chicago franchise, it introduced audiences to a gritty, character-driven police procedural with a strong ensemble cast. But as the years progressed, several high-profile departures reshaped the Intelligence Unit — often delivering heartbreaking goodbyes, startling twists, and lingering effects that changed the trajectory of the series.
One of the most significant departures was Sophia Bush’s Detective Erin Lindsay at the end of Season 4. Lindsay, one of the show’s most popular characters, left Chicago for an FBI opportunity in New York, a sudden storyline driven by behind-the-scenes tensions. Her exit not only created an emotional hole on-screen but also left fans wondering if she might one day return — something that, so far, hasn’t happened.
That emotional turbulence continued in Season 5 with the death of Detective Alvin Olinsky, played by Elias Koteas. A beloved father figure in Voight’s unit, Olinsky was imprisoned and brutally murdered in a jailhouse attack orchestrated by his enemies. The shocking demise of Olinsky highlighted the dangerous and often morally complex world the characters inhabited — a dark moment that still resonates with long-time viewers.
Jon Seda, who played Detective Antonio Dawson on and off across multiple seasons, exited the series after a harrowing arc that saw him spiral into addiction and make morally questionable choices. The character eventually moved to Puerto Rico to reset his life, allowing Seda to exit the show gracefully.
Meanwhile, Brian Geraghty’s character, Officer Sean Roman, was written off in Season 3 after sustaining injuries on duty. Although Roman’s exit was bittersweet — especially given his budding romance with Burgess — it was handled with a sense of realism that spoke to the inherent dangers of police work.
More recently, Jesse Lee Soffer’s Detective Jay Halstead, one of the show’s most beloved characters since its inception, left the squad at the beginning of Season 10. Halstead’s decision to resign and take up a counter-narcotics mission overseas was a pivotal turning point for the series. Fans had long associated him with the show’s heart and moral center, making his goodbye one of the most significant and difficult farewells in Chicago P.D. history.
And finally, Tracy Spiridakos’ Detective Hailey Upton — who had successfully filled Lindsay’s shoes — capped off Season 11 with her own departure. Upton’s goodbye was carefully constructed by the writers as a heartfelt and final chapter, giving the character and fans a satisfying sense of closure.
Each of these exits — from Lindsay’s sudden career pivot to Upton’s heartfelt farewell — underscores one of Chicago P.D.’s greatest strengths: its willingness to evolve, embrace change, and honor its characters. The Intelligence Unit may look different today than it did in Season 1, but its core mission of protecting Chicago’s streets endures.