|Pathology|| Unclassified Killer|
|Modus Operandi|| Unknown|
|No. of Victims||See below|
|First Appearance||"The Fisher King, part 1"|
Not much is revealed about Giles besides the fact that he had a long rap sheet for manslaughter, robbery and rape. At some point, he was hired by Randall Garner, a delusional man who who believed the BAU members to be the Knights of the Round Table and himself to be The Fisher King, to do his bidding in a plot to get the team to rescue his daughter, Rebecca Bryant, from the basement of his house. Randall also hired Marty Harris, a pedophile and convicted fetish burglar. As part of Randall's plan, Giles and Harris went to Montego Bay, Jamaica, where Elle and Morgan went on vacation. On Randall's orders, Giles killed Harris, decapitating him and drawing a trail of his blood to the door of Elle's room. He then went back to Virginia with a red-eye flight and sent Harris's head to Gideon's private cabin. Randall then killed him, impaling him with a sword and using his body to stage another clue for the BAU.
How Giles killed his manslaughter victim is unspecified. When he murdered Marty Harris, he also did it in an unspecified way, and afterwards, he decapitated his corpse.
An official profile was made of Giles, but it was more directed towards Randall, whom the BAU were more focused on and were unaware at the time that Giles wasn't the one stalking them.
- Unspecified dates: Unspecified counts of manslaughter, robbery, and rape
- May 7-8, 2006: Marty Harris