The end of “Adriana’s Pact” hits audiences like a hurricane: As director Lissette Orozco confronts her aunt Adriana Rivas via Skype about her association with Augusto Pinochet’s Gestapo-like secret police, the older woman goes on the attack, screaming at her niece for betraying family ties. Long before then, the viewer knows what Orozco hopes not to believe, but even so, the moment is deeply chilling. “Adriana’s Pact” is a brave documentary in which the director allows us to witness her loss of innocence, and while the exposure must be painful, its rawness will translate to major festival coverage as well as probable specialized boutique release.

Adriana, known in the family as Chany, was Orozco’s idol, her Auntie Mame who would sweep into Chile from Australia laden with gifts and trailing an air of glamour. Then during a visit in 2006, Rivas was arrested and charged with working for DINA, the much-feared secret police during Pinochet’s dictatorship. Her relatives knew, of course, but never told Orozco; as the director’s grandmother says, she never judged Chany because it didn’t impact the family. Besides, Rivas always claimed she simply worked as a secretary and had no idea what was going on in the notorious detention centers.

With her aunt’s knowledge, Orozco began filming their Skype calls in 2010, after Rivas fled Chile while on parole. For the older woman it must have seemed like a way of claiming her innocence (at this stage she swears she never did anything that would make her lose sleep), and for the director it was a means of clearing any doubts from her mind. Rivas’ argument is that she was merely an apolitical secretary dazzled by her sudden access to the Chilean elite at clubs and parties. As counter evidence begins piling up though, Rivas changes her story, saying she did know about the tortures, but was threatened when she tried to quit.

Hoping beyond hope to confirm her aunt’s claims of innocence, Orozco digs into the past, consulting researchers investigating DINA’s gruesome record and even talking with Chany’s former colleagues, all of whom are well-schooled in obscuring the truth. Meanwhile, Rivas doesn’t help her case when she gives an interview in Australia claiming that torture is a legitimate tool that gets good results. Clearly it was foolish of her to speak to the journalist, but Rivas’ narcissism overruled prudence, and Australia’s Chilean community began putting pressure on the government to extradite her to Chile.

As her horrified niece discovers that her aunt’s protestations of innocence are bunk, and witnesses come forth identifying Rivas as actively participating in the torture of prisoners, Adriana takes to lashing out at everyone else and guilt-tripping Orozco. Viewers watch with pained emotion as the body of evidence crushes alternative explanations, and the director, suddenly very much alone, is forced to acknowledge the gravity of her aunt’s crimes. The personal nature of “Adriana’s Pact” probably explains the rough visuals more than budgetary constraints, but few will be put off by occasional cheap digital formats since the subject is so compelling.