David Rossi, a veteran profiler who comes out of retirement, joins the team in season three. Season three focuses significantly on the team’s family lives. Viewers learn about JJ’s long-term partner Will and her pregnancy with their first child, Henry. Though Garcia fights for her life after a gunshot wound in this season, she is also introduced to Kevin, an analyst commissioned to search her computer, who eventually becomes a significant love interest. And, most notably, in this season, Haley, Hotchner’s wife, divorces him.
This event lays the groundwork for the George Foyet storyline. Foyet initially speaks with the BAU, purporting to be the sole survivor of a serial killer known as the Boston Reaper, who attacked him 10 years prior. In truth, he is the Reaper. When the BAU investigates the Reaper, he evades and taunts them, to the point of staging his own murder by draining a convincing amount of blood from his own body.
This storyline extends into season five, in which the Reaper, having escaped custody at the end of season four, attacks Hotch in his own home, holds him hostage, and tortures him. In an act of supreme cruelty, he murders Hotch’s ex-wife, Haley. Enraged, Hotch beats him to death. The psychological scars of this event stay with him, and the BAU, forever.