on another note, i can believe it was caleb.
- he did not willingly leave the cult, so it is reasonable to believe he still believed in their causes/mission
- he goes out of his way to get into quantico because he needs to frame someone. even tho he sucks as an fbi student. he even uses his parents connections even tho that clashes with his independent values.
- he picks parrish after the lie detector tests. once the teacher turns the camera off from detecting her lie, Caleb slow claps when everyone else is silent and mentions Parrish's secret not being as juicy as the dude who kills himself. his initial target was the mormon (his roommate) which would've been easier for him to frame. he settles on Parrish whose secret is so big even the fbi teacher helps her hide it
- once caleb becomes an analyst he has the resources to find info to blackmail the gay analyst dude who will also kill himself.
- caleb didn't know his mom was gonna be the candidate for the convention he was ordered to help bomb. once he finds out he immediately tries to ruin things by telling his dad that she is just using him like she always does. later he tries to get his mom to quit again by telling her about the affair. even tho he villainized her the first time this time he states he told her because he cares about her
- he gets close to Shelby whose company owns the rare materials he uses to make the bombs. He even breaks into her computer with the excuse he was doing it just to expose her sister
- he is the one who lured charlie in. both run in the same circles. Caleb was let into Quantico based on the word of the FBI director while Miranda is the assistant director. it is likely Caleb & Charlie have met before. Both hold grudges towards their parents & the lifestyles provided to them.Caleb uses this info to prey on Charlie. He even manages to kidnap/break into Miranda's home cuz really he wanted access to info for his bombing of the DNC
this is what i can remember, i'm sure there will be more clues if i re-watch. but basically caleb went out of his way to get into Quantico, he had access to all the info & people, and he tried to prevent his mom from the DNC bombing but his loyalty was to his cult first
plus the charlie thing really points to caleb cuz it seems so out of place. but they're not gonna add that part to the storyline unless it plays a part. Charlie is basically a less extreme version of Caleb
i'll have to re-watch one scene to see how it ties in, but Charlie asks his mom near Caleb if she thinks he'll ever be an FBI agent. the question does seem kinda out of place considering his history/personality, but it is possible he was told to ask the question to prove to him his mom didn't believe in him. i believe she does say no which was odd cuz Caleb used to be in a dangerous cult and managed to get in + the FBI accepts reformed criminals all the time