During Season 3, FBI profiler Gideon (Mandy Patinkin) begins to doubt his abilities and sanity in the aftermath of the murder of his girlfriend at the end of last season and ultimately leaves the BAU. Hotch (Thomas Gibson) is under pressure from Section Chief Erin Strauss (Jayne Atkinson) to resign the Behavioral Analysis Unit (BAU), and Prentiss (Paget Brewster) submits her resignation rather than get dirt on him for Erin. David Rossi (Joe Mantegna) returns to the unit he helped found and eventually gets involved in an extremely cold case that continues to haunt him. This season, the team is confronted with cases involving all manner of killers, including one cannibal. In a two-part episode, Derek (Shemar Moore) must confront his crisis of faith. In another episode, Reid (Matthew Gray Gubler) attends a support group for his addiction. Two cases hit particularly close to home. In one, a team member is shot, and in the explosive season finale, another is targeted by terrorists.