Long backseated to campus and art house, the non-fiction genre has in recent years undergone spectacular commercial renaissance, to a point that some few do actually outdraw their fiction brothers. Complete with rhyming plays on the initial “docu-“ syllables, subcategories have developed, and what in infancy were travelogues, newsreel fragments (sometimes faked) and, later, compilations, have evolved a range of techniques. Historical footage and stills vie with varying doses of re-creation, interviews weave in and out with or without benefit of narration, objectivity is attempted or, in Erik Barnouw’s view, “deception [made] more plausible,” the filmmaker absent chronicler or at the very center as celluloid op-ed auteur.

New approaches doubtless will be imagined, but at present, most viable methods seem pretty well covered. The choices made, their selection and arrangement, are for the moment the documentarian’s province for originality, his or her canvas for presenting facts and maybe creating reaction or influencing opinion.

Director of Oscar-winning The Fog of War Errol Morris cautions against “confusing film with truth, something you pursue and never arrive at. . . . The whole idea that you can read truth off a piece of celluloid in and of itself is a very dangerous notion.” How, then, to read Oscar-nominated director-writer-coproducer Paola di Florio’s Home of the Brave, a journey to unravel the truth of past mystery but finally a confrontation with that truth in 2004?

Technically, the hour-and-a-quarter film offers little out of the ordinary, from narration by Stockard Channing to archival film centered about Bloody Sunday and the four-day Selma-to-Montgomery Voting Rights March convoked by Martin Luther King, Jr. Her voice never heard directly, her person seen as much as anything in gruesome coroner’s b&w’s, Viola Gregg Liuzzo is the starting point -- taken from the Mary Stanton book, From Selma to Sorrow -- yet her five children, and their accommodations over intervening decades, are the focal point, as middle daughter Mary follows her mother’s path in a Detroit-to-Selma drive, to Highway 80 and the Edmund Pettus Bridge.

Many of them martyrs to violence, they live in hearts, minds and song -- Dr. King, Medgar Evers, the four young girls of the Sixteenth Street Baptist Church, Goodman, Schwerner and Chaney -- but the sole white woman murdered in America’s civil rights movement, thirty-nine-year-old Mrs. Luizzo, headlines a brief while after that March 25, 1965, is today less than a footnote, gone but forgotten.

The “why” of that oblivion is explored here, although the answers are nowhere near a hundred percent -- too long ago, too much official obfuscation, and bizarre testimony from an in-hiding Leroy Morton, the young African-American passenger in Liuzzo’s Oldsmobile when she was shot in the face supposedly from a car filled with Klansmen and an FBI informant. The suspects were acquitted by an all-white, all-male state jury, then convicted of violations of civil rights by a subsequent federal court, and years later new findings implicated as triggerman (and possible participant in the Birmingham church bombing) that same immune-from-prosecution informant. The film considers the scope and size of the FBI file on Liuzzo, the leaks from that source to discredit her character through innuendo about drugs and promiscuous interracial sex, and the fact that her husband Jim was “a close friend of Jimmy Hoffa’s” and, according to J. Edgar Hoover, “a known Teamster strongman.”

Growing from this distressing, probably unresolvable tale of cover-up and incompetence, and tied to it via Mary’s visiting Viola’s friends and the SCLC-markered murder site and nearby welcoming black church, is that of the young children left motherless and in denial. Bewildered by slanders against their dead parent, and racist slurs and burning crosses directed against themselves, they withdrew, particularly after the two sons lost a suit against the government and were ordered to pay costs. Akin to its Sundance companion made by the Rosenbergs’ granddaughter, Heir to an Execution, Home of the Brave traces the effects of past events on family members who must go on living.

Saddest and most frightening among the grown traumatized offspring are the youngest, Tony, firearms-freak second-in-command of the Michigan Militia, voice of 88.3 Radio Free Michigan (“fighting tyrannical government”), gone underground after the Patriot Act; and the eldest, Tommy, former civil rights participant turned backwoods Alabama recluse who leaves behind hanged black dolls.

Having given the latter up for lost, the sisters “had always thought we’d have Tony around” but now fear that another “casualty” awaits them. The Liuzzos are victims and casualties, along with Justice and Truth and concerned citizens, too, in the land of the free and Home of the Brave. Conspiracy theories haunt the corridors, and though this film cannot pinpoint the root cause, it stirs us. The content, not the container, the theme rather than the method, affects the viewer, for it touches race and society, group and individual, mother and children, generation to generation.

(Not rated by MPAA.)