Grief stricken about the death of his girlfriend Sarah, Gideon retreats to his summer cabin to recover, while the rest of team investigate the death of several campus women in Arizona. After the UnSubs are killed, Hotch gets a two-week suspension for his actions from Erin Strauss and Gideon’s leaves the BAU for good, leaving the team in shambles. Gideon leaves a letter for Spencer but no one knows where he has gone off to. With Gideon missing, and Hotch and Prentiss off the team, Prentiss having resigned and Hotch seeking a transfer, Morgan, Reid and JJ investigate one of its most difficult cases yet as they track a serial killer in Milwaukee who’s abducting women in public places by using his son as bait.
With Hotch & Prentiss back in the fold, the team minus Gideon go to assist assist local authorities in investigating the disappearances of people who are new to Portland and have no strong social ties in the city, home invasion murders in Denver and to locate a small girl who went missing in a huge shopping mall in Virginia (the last one is a really good episode). Retired SSA David Rossi (Joe Mantegna) rejoins the BAU having got tired of his 10 year fame as an author, just to time to find a serial killer in Dallas who scares his victims with “missing” flyers that display the soon-to-be victims’ photos and kills them by taking off their faces. Garcia meets a man who she thinks is her dream man but is shot by him at the end of their first date and left for dead.
As Garcia fights for her life in the aftermath of her shooting, the BAU rally around her and also begin searching for her attacker which leads them to believe the assailant could be someone close to the investigation. Next up is a comic book artist who is psychotic and then go to the investigation of a series of mutilation murders that appear to mimic similar crimes that had occurred over two decades earlier. Two teenage girls are abducted and one is killed while the other is tied up and happens to be in a witness protection program. Rossi must deal with the death he couldn’t solved 20 years ago of the parents of 3 kids. he is joined by Prentiss, JJ, and Morgan when they learn about the case. Meanwhile, Hotchner and Reid interview a death row inmate in a Connecticut prison, but the interview doesn’t go as they expected when the prisoner reveals his motive for calling them. The BAU is called to Pittsburgh after an unusually high suicide rate appears to be the work of an angel of death and to a Texas town where a teenaged boy & girl, both victims of bullying, are involved in a killing spree.
While in Miami to catch a gender confused killer, JJ finally ‘confesses’ about her affair with Will to her team (who already know). She is also pregnant. Hotch and Rossi are called as consultants on a possible battered woman syndrome murder case in Boston, while the rest try to identify a stalker before he can attack a woman. And in the toughest case yet, the team is called to NYC to determine if a series of random shootings is the work of one serial killer or a team of killers working together. The episode ends in a cliffhanger as everyone gets into their separate cars and then one of the SUV’s explodes. We don’t know who was in the car among the team until season 4. Really awesome season.