One of the many killers the team investigates is Gormogon (Laurence Todd Rosenthal), a mysterious figure with cannibalistic tendencies who harbors obsessions with secret societies and government conspiracies. Gormogon manages to evade capture for a while, though it soon becomes evident that he's not working alone. Gormogon has an apprentice to help him commit crimes and before their identity was revealed, viewers suspected that Sweets could be the culprit. At first glance, it's not a bad theory.
Even though Sweets is known for his mild-mannered demeanor, his work as a psychologist gives him access to the inner workings of the people around him. He is adept at observing body language, a valuable skill for a killer trying to evade detection. As Reddit u/findingscarlet pointed out, Sweets was introduced "to specifically poke and prod at Booth and Brennan, find their weak spots, and evaluate them for the FBI."
For some viewers, both Sweets and his girlfriend Daisy Wick (Carla Gallo) raised suspicion. "I was fully convinced of Sweets or Daisy. The former started asking really strange questions, and the way that he was talking about getting into the mind of Gormogon and defending him from these random suggestions made it seem pretty shady," writes Reddit u/dangerouslyaware. Sweets' late introduction combined with his professional abilities seemingly make him a great candidate to be Gormogon's apprentice. Even Booth and Brennan even suspected as much at one point.
However, the apprentice's true identity proved to be even more shocking.