As the mainstream media shuts down foreign bureaus and cuts back on investigative journalism, “documentary film is filling that void,” says Matthew Heineman, 34, as he and his fellow documentarians gathered at THR’s Documentary Roundtable. Heineman’s own film, City of Ghosts, focuses on the citizen journalists who risked their lives to get word out from Raqqa, Syria. His fellow filmmakers are no less engaged with real-world issues: Cries From Syria, from Evgeny Afineevsky, 45, recounts the country’s searing civil war; The Final Year, by Greg Barker, 54, offers an inside look at the Obama State Department; The Force, directed by Peter Nicks, 49, chronicles problems within the Oakland Police Department; and Step, from Amanda Lipitz, 37, tells how being part of a girls’ step dance team instilled confidence in a…