EXCLUSIVE: Chicago P.D. female lead Sophia Bush is leaving the NBC cop drama series after four seasons, I have learned. She is the second key Chicago P.D. player to depart, along with co-creator/showrunner Matt Olmstead, who left in March.

I hear Bush is leaving on her own accord. A possible exit for the actress was hinted in the recent Season 4 finale of Chicago P.D, which saw her character, Detective Erin Lindsay, on the verge of accepting a job with the FBI in New York. The episode ended with a cliffhanger, with Lindsay standing on a bridge, ignoring Jay (Jesse Lee Soffer)’s call.

I hear there is a possibility for Bush to return for a guest-starring arc to wrap her character’s story. I hear the show is mulling bringing in a new prominent female cast member though it also may stick with its remaining cast. NBC and reps for Bush declined comment.

Bush’s departure is a loss for the entire Chicago/SVU franchise, which has the characters cross over between shows. She has appeared in 22 episodes total of the other three Chicago series and Law & Order SVU.

Like the mothership Chicago Fire, Chicago P.D. is a testosterone-driven series, with a mostly male cast and crew. The Chicago P.D. set had been described as a tough environment for a female performer. There have been below-the-line changes made on the show, including replacing long-time executive producer/director Mark Tinker with Eriq LaSalle earlier this month.

Outside of acting, One Tree Hill alumna Bush has been devoting much of her time on charity work, with environmental, social and gender equality causes as her primary focus.