a Nova/WGBH production ; produced by Matthew Barrett, John Rubin, and Sarah Holt ; written by John Rubin ; directed by John Rubin, Rushmore Denooyer, Serena Davies, and Sarah Holt
a co-production of JTN Productions and Thirteen ; in association with NDR and WNET.org ; produced and directed by Mike Dewitt ; written by Mike Dewitt, Daniel Jonah Goldhagen
a Frontline co-production with RAINmedia, Inc. ; a production of WGBH/Boston ; written and produced by Martin Smith and Marcela Gaviria ; co-produced by Will Cohen
a Nova production by Hamilton Land & Cattle, Inc. for WGBH-Boston ; WGBH Educational Foundation ; Written and produced by Doug Hamilton ; associate producer: Solana Pyne