PARK CITY -- Robinson Devor's "Zoo" removes itself from the realm of bawdy jokes to examine the shocking 2005 incident in which a Seattle businessman died of a perforated colon after having intercourse with a stallion. The death led to an investigation into a horse ranch near the town of Enumclaw, where videotapes were discovered of men having sex with horses. Since bestiality isn't a crime in Washington, no one was charged, but, ironically, the horse in question was gelded.

As one would expect, the media and its pundits had a field day with the sensational news. Devor takes such an opposite approach that anyone seeking a cheap thrill will be soundly disappointed with "Zoo." Whether meaning to or not, Devor and his accomplished crew expand our concept of the documentary film, which relegates this docu to art houses, not porn theaters.

Devor, whose previous films have been features ("The Woman Chaser," "Police Beat"), screenwriter-journalist Charles Mudede and cinematographer Sean Kirby reject many of the techniques one associates with documentary filmmaking in favor of an impressionistic study of men who surrender to extreme appetites.

Necessity may be the mother of invention here since the protagonist was dead and many individuals did not want to appear on camera. In any event, "Zoo" utilizes dramatization, much as Errol Morris did in 1988 with "The Thin Blue Line." With these staged scenes, featuring either actors or actual participants, the film examines the phenomenon of "zoophiles," a community that gathers first online and then in clandestine meetings where such appetites are taken for granted.

The men speak with remarkable candor of their "love" for animals, portraying this as a natural desire and not as a morally repugnant activity. While the repulsed judgments of others seep into the film through sound bites from talk radio, mostly the film lets members of the apparently all-male society of zoo speak for themselves.

When one man insists that the sex takes place "with an intelligent being who is very happy to participate," you recognize the need to rationalize. How do they know the horse is "happy to participate"? Mostly, these are men cut off from friendships in human society; indeed, they don't like to deal with human relationships all that much.

Cool, lush, dark colors reflect the gray Washington skies. Joe Shapiro's lyrical editing deliberately emphasizes the bucolic, while Paul Matthew Moore's score has an ominous, Philip Glass-like quality.