The BAU is called to the San Francisco Bay area when a young couple named David Atley and Nicole Puli are found shot to death, with evidence pointing to the unsub being the Zodiac Killer, who has not been heard from since 1974. The local police detective leading the investigation believes it to be the work of the real Zodiac Killer, but Hotch, Rossi and Reid believe that it is not, especially since there has been no evolution in the nature of these latest killings since those by the real Zodiac Killer. The team nonetheless follow leads back to the original investigation, including tracking those who were involved in that investigation as well as anyone who either wrote about it or tracked the investigation. They are hindered in the investigation by an anxious and sometime media hungry public who want to cash in on the Zodiac Killer's notoriety. They are also helped and hindered when they learn the unsub has a genius IQ, he who may understand the BAU's tactics. As the BAU goes through their investigation, the unsub takes his childhood best friend on an unwanted trip down memory lane, which could be his and that best friend's downfall. Meanwhile, Reid, on meeting a fellow prodigy at a violent crimes seminar, questions whether he has achieved enough in life - which includes choosing to be an FBI agent - as he hits the milestone age of thirty.
Special Agents Jason Gideon (Mandy Patinkin) and Aaron Hotchner (Thomas Gibson) head up the FBI's most elite profiling team - experts in analyzing criminal minds. Each team member has their specialty. There's Elle Greenaway (Lola Glaudini), who has a background in sexual offences; Derek Morgan (Shemar Moore), who focuses on obsessional crimes; Special Agent Dr. Spencer Reid (Matthew Gray Gubler), the smart-but-socially-challenged genius; and Jennifer "JJ" Jareau (A.J. Cook), the rookie. With each mind-blowing case, they put their lives on the line as they match wits with the most ruthless criminals on earth.
Following an explosive face-to-face encounter with “The Chameleon,” Reid suffers from a brain injury and, while experiencing hallucinations, is visited by ghosts from his past. The BAU makes a shocking discovery about Lynch that affects Rossi personally. The entire team comes together to celebrate Rossi’s retirement.
It has been a year since Rossi nearly died at the hands of Everett Lynch—aka “The Chameleon”—and he has developed some new theories, with inspiration from his former partner, Jason Gideon. The BAU team sets out on an epic hunt to capture Lynch.
Prentiss and J.J. are faced with important decisions to make about their futures as the BAU travels to Beaumont, Texas to investigate a series of murdered businessmen
When the BAU team travels to Denver to investigate several murders, Prentiss is forced to evaluate her relationship with Special Agent Andrew Mendoza.
After a father and daughter get kidnapped, a former foe of the BAU returns with very specific demands for Dr. Reid that give a whole new meaning to the phrase “wheels up.”