The San Francisco team investigates the mysterious deaths of patients in intensive care, who were being treated by a doctor known to be sympathetic to mercy killing.
A man finds his wife's dead body in the trunk of his car, with her heart removed. Branca, Rivers and Enright travel to Port Endicott, Oregon where there have been similar cases.
A string of murders lead the OSC to Boston and to Father Bob Di Fabian who heard the Blade Runner's confession.
A couple is found shot in their own home and their son is missing. Their murder is connected to a string of murders done by a man nicknamed the Morning Person.
A girl named Emily Akins is murdered, and the suspect is Mr. Clean, a serial killer who is out on parole but is missing.
The bodies of three men are found at a monument. They all have the same heart tattoo and drilled holes in their heads.
The team are searching for a serial killer, nicknamed the Hangman. Stephen Laney, a reporter and a former acquaintance of Branca's, has been following the Hangman's murder spree for a year.
Three women are found beaten to death outside of a strip club. All three were dressed like Justine Hazelton, a former prostitute serving time for murdering six pimps in the early 1990s.
A woman is burned to death with strange markings on her body, which draws similarities to a previous victim. Creegan and Branca investigate, and think their perpetrator is man obsessed with fire.
Returning from a year-long psychological leave of absence after surviving an almost-fatal gunshot wound to the head, Detective David Creegan is assigned to the FBI's Organized and Serial Crime Unit – a rapid-response, elite crime investigation squad – where he and his new partner, Detective Susan Branca, find themselves committed to saving lives and solving cases. In spite of his inability to abide by common sense and the laws he's sworn to uphold, Creegan, with the help of Branca, works on hunting down the most vicious criminals on the streets.