Jack first appears in the show's pilot episode Two of a Kind, where he promotes Simms after the Red Cell team closes a case in Cleveland, Ohio. He has later made a handful of other appearances in the season.
In the episode "The Time is Now", it is revealed that Fickler was once a BAU Team Leader, and becomes the central character when an unsub, Veronica Day, that he profiled a decade ago is granted a new trial. His profile is put into question and he asks Cooper to help him and to testify in open court. In a surprising twist, Day turns out to actually be innocent of one of the murders she was accused of, because the original ADA did not release exculpatory evidence to the defense.