As a team member fights for life, the BAU continues the search for an attacker that leads the unit to believe the assailant could be someone close to the investigation.
The BAU team closes in on the serial killer as he continues his murder spree throughout Los Angeles - with Detective Spicer's kidnapped daughter as his hostage - in the conclusion of last season's cliffhanger.
When several women in Herndon, Virginia, are found murdered in a similar manner, SSA David Rossi reopens an unsolved cold case that has haunted him for a quarter of a century because he believes the original killer, who is suffering from Alzheimer's Disease, might have returned.
The BAU team travels to San Francisco to investigate the murders of several homeless men and teams up with a separate group of BAU operatives who are working another case they think is connected.
A series of rolling blackouts in the city of Los Angeles lures a serial killer out of hiding, giving him renewed opportunities to continue his killing spree.
An elite team of FBI profilers analyze the country's most twisted criminal minds, anticipating their next moves before they strike again. The Behavioral Analysis Unit's most experienced agent is David Rossi, a founding member of the BAU who returns to help the team solve new cases.