“Reporter” bears witness to the work of New York Times columnist Nicholas Kristof, whose Pulitzer-winning coverage of humanitarian crises worldwide has helped elicit constructive outrage and U.N. intervention. Narrated by filmmaker Eric Daniel Metzgar, this intelligent, moving docu observes Kristof in war-torn Congo and explores his belief in the phenom of “psychic numbing” — the more victims portrayed, the lesser the degree of public compassion. As if testing this theory, Metzgar zooms in tight on Kristof himself, resulting in a vivid characterization of an impassioned journalist — for an aud, one trusts, that’s far from numb. Pic airs on HBO this spring.

Kristof, an Oregon-reared, Harvard-educated Rhodes scholar, appears to be a man of iron will and eerie composure. That Congo has seen the violent deaths of 5.4 million in the past decade doesn’t deter the reporter from patiently discovering a particularly heart-rending subject — a victim of rape, infection and starvation. “Reporter,” whose climax finds Kristof in tense conversation with rebel warlord Laurent Nkunda, doubles as an urgent plea for the survival of investigative storytelling in print. Tech credits are amazing when one considers the myriad dangers of the setting.