When guards at a Virginia prison intercepted a package with evidence relating to the kidnapping of two boys several years ago, the BAU questioned a notorious serial killer who had information on the victims' whereabouts.
Follow the trail
"The Devil's Backbone" isn't just the title of this week's Criminal Minds episode—it's also a reference to a famous rock formation located just outside of Louisville, Kentucky.
Cover to cover
The fictional novel "The Viscount and the Maiden," featured seen in this week's episode, came from the Criminal Minds' art department.
The correct pronunciation of the word "viscount" is with a long "i" and a silent "s." Criminal Minds writers used the mispronunciation of "The Viscount and the Maiden" in the episode as a nod to fans of historical fiction.
Random fact about UnSub Claude Barlow: He owned three Doberman pinschers.
The notorious Antonia Slade was sent to solitary confinement after dousing a prison guard in rubbing alcohol and lighting him on fire in 2002.
Big news: Morgan's office officially has a new occupant. Hotch gave Derek's empty office to the FBI's Expert Advisor Program.
Who's that lady? UnSub Claude Barlow's home contained surveillance photos of a younger Antonia Slade.