John Edgar Hoover (played by Eric Ladin) is the newly-appointed head of the Bureau of Investigation in America. He is a recurring character in Season 4 and rival to Agent James Tolliver.
| Season four appearances | |||
| "New York Sour" | "Resignation" | "
'Acres of Diamonds'" |
"All In" |
| "Erlkonig" | "The North Star" | "William Wilson" | "The Old Ship of Zion" |
| "
'Marriage and Hunting'" |
"White Horse Pike" | "Havre De Grace" | "Farewell Daddy Blues" |