A not-too-bright white supremacist
Let's see. A young, pretty woman who nobody has ever met or knows comes to town to work. Gary Simmons (the white supremacist leader) falls for her, and then they sleep together. A short time after that, he takes her "hunting" (chasing a scared black teen in the woods and killing him) and later to Klan camp.
I don't know too many white supremacists. But from what I've seen from documentaries on A&E, the History Channel, etc. they are all paranoid and know that the authorities as well as watchdog groups are watching them.
You'd think an experienced white supremacist would immediately suspect her of being an informant or an undercover agent and thus avoid her.
I also read somewhere that a significant percentage of KKK members are either paid government informants or undercover agents. (I don't know about other hate groups.)