Here's What Makes Criminal Minds Killer Frank Breitkopf So Twisted

The intrepid agents of the BAU have faced down many ruthless and monstrous serial killers over the years, but one of the most memorable Unsubs in the history of "Criminal Minds" is Frank Breitkopf (Keith Carradine). Debuting during the show's second season, Frank would only make two appearances on the show, but each of them had a profound impact on the series, effectively ending the status quo of the BAU up until that point. Frank managed to elude capture when he first encountered the BAU, and while they were able to run him to ground, he still had a final ace up his sleeve.

Frank's actions were so awful and his final fate so grim that he left lasting scars on the psyche of Agent Jason Gideon (Mandy Pantinkin), to the point he resigned from the BAU. While his time on "Criminal Minds" was brief, Frank definitely had an impact, effectively upending the BAU and leaving wounds that would never fully heal. Here's what made this serial killer so twisted.

Debuting in the second season episode "No Way Out," Frank is a ruthless sexual sadist who has killed over 170 victims without a flicker of remorse. The only child of a single mother, Frank watched as his mother turned to prostitution to support them, the experience turning him into a sexual sadist who fed on the fear of others. Traveling the country in a trailer, Frank would stalk and murder victims, paralyzing them with a potent drug and then placing them on a makeshift autopsy table under a mirror. This enabled the victims to watch as he slowly removed their organs while they were still alive.

Abducting a troubled woman named Jane Hanratty (Amy Madigan), Frank initially planned to make her one of his victims, but when she looked upon him calmly as she lay on the table (believing him to be an alien abductor), he released her. Later, Frank would claim he fell in love with Jane and would return to her home town of Golconda, Nevada every year to leave her wind chimes (made from the bones of his victims).

The first time Frank faced off against the BAU, the unit was called in to investigate his more recent killings, which led them to Golconda. Jason Gideon and the team managed to corner him in a diner, but not before Frank revealed a hidden ace up his sleeve: a bus of schoolchildren he'd hidden in the desert. Bartering their location in exchange for his and Jane's release, he managed to escape custody, disappearing into the desert with Jane.

Frank reappears in the second season finale "No Way Out II." Appearing at Jason Gideon's apartment, he murders Gideon's girlfriend Sarah Jacobs (Moira Squier) and proceeds to stalk and kill previous would-be victims that Gideon and the BAU have helped to save. Eventually cornered by the BAU, a reunited Frank and Jane elect to commit suicide rather than be taken into custody. The loss of Sarah and witnessing Frank and Jane's suicide proved too much for Gideon, who elected to retire from the BAU in the second episode of the third season "Name And Blood."

Frank Breitkopf was a twisted killer and a monster whose actions hurt countless innocents and whose callousness and cruelty broke one of the BAU's best agents. While his time was brief, his impact on "Criminal Minds" cannot be understated.