Does the world truly need a graphic documentary devoted to the life of Issei Sagawa, a notorious Japanese murderer who shot and cannibalized his classmate in Paris in 1981? That is the question raised by Vérena Paravel and Lucien Castaing-Taylor’s Caniba (making its North American premiere at the Toronto International Film Festival), which focuses on the aftermath of Sagawa’s grisly shooting of his fellow Sorbonne student Reneé Hartevelt, the rape of her corpse, and his subsequent consumption of her flesh over a two-day period.

Paravel and Castaing-Taylor are unlikely provocateurs. Both filmmakers are anthropologists that hail from Harvard University’s Sensory Ethnography Lab, a launching pad for some of the most vital experimental work in contemporary documentary cinema. An opening credit expresses the filmmakers’ disclaimer that the film does not “seek to either justify or legitimize” Sagawa’s crimes. That being said, Caniba, which, in the spirit of other films made by the SEL, spurns any pretense of objectivity and offers viewers an “immersive” viewing experience, inevitably feeds off the macabre fascination with Sagawa’s psychosis that has made him something of a minor celebrity in Japan and even inspired songs by the Rolling Stones (“Too Much Blood”) and the English rock group The Stranglers (“La Folie”), which is played over the film’s end credits.

Amazingly enough, although Igawa was incarcerated in a French mental hospital for several years, he was eventually granted his freedom since, after being deported to Japan in 1986, the French charges against him had been dropped. Paravel and Castaing-Taylor’s film chronicles his recent life in Japan, in tandem with the only slightly less shocking (although fortunately non-homicidal) sexual obsessions of his brother Jun. For reasons that remain fuzzy, Jun, a less than wholly stable individual himself, has been entrusted with caring for his deranged brother.

For a grueling 90 minutes, the camera lingers on an extreme close-up of Igawa while his brother’s face is visible, for the most part out of focus, in the background. Unlike conventional investigative documentaries, the film eschews talking heads or explanatory snippets of voiceover. True to their agenda of offering viewers a visceral rather than a purely cerebral experience, Caniba is not preoccupied with facile explanations of Igawa’s behavior, whether psychoanalytic, sociological, or even—despite the filmmakers training—straightforwardly anthropological. Instead, the film’s documentation of this bizarre antihero’s ruminations, in both Japanese and French, confirm that Igawa views his cannibalism as a warped form of l’amour fou, a necrophilic attempt to romantically fuse his body with a love object that is reminiscent of some of Edgar Allan Poe’s darker fantasies.

Many of these deadly preoccupations come to the surface in a sequence devoted to a manga Igawa drew illustrating his transgressions—ostensibly in a futile bid to make some fast cash. Igawa’s drawings possess a creepily superficial resemblance to the work of the American outsider artist Henry Darger known, or perhaps infamous, for his work depicting the torture of young girls.

Even Jun admits that this misbegotten manga makes him want to “throw up.” Of course, it’s difficult to take his misgivings seriously since Paravel and Castaing-Taylor include a protracted sequence devoted to Jun’s unsavory form of masochism, an assault on his body that takes the form of aggressive self-mutilation with both knives and barbed wire. Although it’s reasonable to wonder what sort of childhood produced such disturbed individuals, the film merely produces some rather innocuous home movie footage of the brothers as children that prompts the cannibalistic sibling to interject that they resembled twins in their early years.

For years, anthropologists have surmised that cannibalism may well have its roots in either “religious” or “psychosexual” motivations. As a 1986 New York Times article asserts, “cannibalism is never just about eating.”

Paravel and Castaing-Taylor hint at this sort of anthropological speculation by featuring a quote from the Gospel of John: “Whoever eats my flesh and drinks my blood remains in me…” Nevertheless, Caniba, like most avant-garde films, refuses to be reductive and, to the frustration of many critics and audience members, leaves definitive interpretations up to the audience.

Rather predictably, Caniba is far from a crowd-pleaser. Audience members have walked out in droves and even critics who were sympathetic to Castaing-Taylor and Paravel’s previous work are wary of the movie and fear that the end result may be more exploitative than illuminating. It’s arguable that, as with many challenging films, it may be premature to issue a final judgment. As Castaing-Taylor told The Globe and Mail: “If we refuse—as filmmakers, as artists, as intellectuals, as anthropologists—to address subjects that challenge us ethically and intellectually, then we leave a record for the future that is divested of everything that makes us real. There’s nothing more real than being in a situation of ethical ambivalence. We’re all confronted with ethical ambivalence every day of our lives. The idea of retreating from a subject because it makes us uncomfortable seems to me very cowardly.”

Still, it’s difficult to come away from Caniba without thinking that Castaing-Taylor and Paravel want to have it both ways—they relish the outrage caused by a scandalous film yet rush to defend it as a product of anthropological detachment and “ethical ambivalence.”