If you're interested in the meddling those Civil Rights people did, try picking up a book called
Klandestine. It is the story of Delmar Dennis who infiltrated the Ku Klux Klan for the FBI. In large part it regards those two Jews and the black kid, Schwermper, Goodman, Chaney, who were killed by Sam Bowers's, Ku Klux Klan -- probably the most dangerous klan btw....
I think the new price is way too expensive so maybe you can get the used version.