'Informant' (unrated)

Brandon Darby, the subject of writer-director Jamie Meltzer’s absorbing documentary Informant, talks into the camera with a mixture of indignation and frustration and arrogance. At times, he stops in mid-sentence and walks out of the shot, muttering about how “the left” blames him for everything and how he refused to accept an offer by the U.S. Attorney’s Office to enroll in their Witness Protection Program. Other times, he is calmer, more focused and eloquent, even as he’s making hugely inflammatory statements about fomenting radical social change by whatever means necessary.

The movie includes footage dating back to 2005, when Darby traveled from Austin to New Orleans to help rescue a friend stranded by Hurricane Katrina. When he saw how those affected by the storm had been left to fend for themselves by the government, he formed a collective called Common Ground Relief, through which he and some like-minded activists (including Scott Crow and Lisa Fithian) helped provide food and water to the victims under the watch of local police authorities, who were wary of what these strangers were up to.

In those days, Darby identified himself with the spirit of the Black Panther Party and even traveled to Venezuela to ask then-President Hugo Chávez to provide assistance, hoping to shame the U.S. government into action. To his fellow volunteers and the citizens of the Ninth Ward district of New Orleans, Darby was a hero.

But then things started to change. Like a gripping suspense novel, Informant recounts how Darby became an unlikely informant for the FBI after moving back to Austin and how his first tip — which proved to be a false lead — resulted in a man’s suicide. Instead of being discouraged, though, Darby became a proactive double agent of sorts, infiltrating an Austin group of college-age demonstrators who were planning to protest the 2008 Republican National Convention and nudging them to commit a crime that resulted in two controversial arrests and prison sentences.

Today, Darby is a spokesman for the Tea Party, was hailed as a hero by the late conservative blogger Andrew Breitbart and lives in constant fear for his life due to death threats. His story is so complicated and political that the movie could have easily slipped into hagiography or critique. One of the miraculous things about Informant is that the film passes no judgment on Darby, even though everyone else interviewed in the film does. This timely documentary, which illuminates the ways in which government agencies spy on and track normal citizens, also passes the test as a work of balanced journalism about a man of fascinating contradictions.

With: Brandon Darby, Scott Crow, Lisa Fithian, Caroline Heldman.

Writer-director: Jamie Meltzer.

Producers: Steve Banntyne, George Rush.

A Music Box Films release. Running time: 81 minutes. Vulgar language. Opens Friday Oct. 18 in Miami-Dade only: Bill Cosford Cinema.