The BAU believes two unsubs may be operating at the same time, when victims killed in two different ways are discovered in the same city.
The BAU investigates when several men and women are victims of disfiguring acid attacks; Reid begins to settle into his new surroundings.
A mother steps forward with valuable information for the BAU to aid in their investigation of an unsub known as the bone crusher.
Let It Bleed. Still reeling from the death of informant Anna, Voight faces a new threat as he tries to keep the neighborhood clean.
Grissom and Sara's investigation into charges against David Hodges heats up; a video game developer's body is found floating in a fountain before a gaming tournament.
