He lived in London for most of his adult life , and became a freelance journalist and war correspondent , working with organizations such as CNN , BBC and Reuters . He turned to filmmaking in 1998 , and made a string of international films for the flagship PBS television series Frontline . Barker spent seven years researching the Rwandan genocide , which resulted in the feature-length Frontline documentary '' Ghosts of Rwanda '' , which won numerous awards and established his reputation . Barker , produced and directed one or more episodes of the PBS series '' God in America '' , using the PBS branded voice Campbell Scott , the series has been updated to the point of President Barack Obama 's inauguration
Rwandan genocide
Rwandan genocide
Greg Barker