Officer Sean Roman's departure from Chicago Pd in season 3 was due to a combination of character development and actor Brian Geraghty's desire to pursue other projects. Roman's retirement from the police force was a result of being shot on duty, leaving him with nerve damage in his arm and unable to continue working in the field. Despite leaving the show, Roman returned for an episode in season 7, where it was revealed that he had killed the drug dealer responsible for his sister's death, leaving viewers questioning his hero status.

Officer Sean Roman quickly became a core member of the cast of Chicago Pd after joining the Dick Wolf show in season 2 ― but only made it to season 3 before leaving the series. Roman, played by Brian Geraghty, underwent a lot of character development in his short time on the show, but his exit meant a lot more potential went unfulfilled.