Sam Hunt Click to see full answer. Thereof, did mouse leave Chicago PD?But what we didn’t know for sure was if Mouse was really going to leave. And, apparently, he was. The deleted scene, posted on the show’s official Twitter page, features the gang at Molly’s toasting him and bidding him farewell.Furthermore, who left Chicago PD cast? EXCLUSIVE: After seven years on Chicago Fire, Chicago P.D. and Chicago Justice, Chicago P.D. star Jon Seda is exiting the popular NBC drama franchise. Also departing are Chicago Med co-stars Colin Donnell and Norma Kuhling. All three are leaving as series regulars. Thereof, when did Mouse join Chicago PD? Mouse is first introduced in “A Beautiful Friendship” as Jay’s CI, assisting him with a case. The two seem to be very close, although no one explains why or how, and he is not seen again until the next season.Why did Elias leave Chicago PD?Chicago PD showrunner Rick Eid has spoken out about the death and revealed that the writers decided to write Olinsky off the show—actor Elias Koteas did not choose to leave. “The writers and I kept coming back to this idea that Voight’s decision to kill Bingham should cost him something.