The Most Dangerous Animal of All

The most notable directorial achievement in this series is its structure, establishing both doubt and certainty as it weaves together the basic beats of the Zodiac Killer mystery with Stewart’s stubborn insistence that his birth father was the infamous (and still unidentified) serial killer who terrorized the Bay Area in the late '60s and early '70s. ... Although Davidson is unafraid to wade into the messy emotions surrounding such a sensational story, he never paints his subjects as anything other than fallible people with complicated motivations.

On the whole, the documentary combines a number of niche interests: docuseries, true crime, and the Zodiac killer specifically. Its four-episode counts makes it an easy investment, one whose ultimate turn is bizarre but feels like a perfect fit for this strange case’s natural twists.

“The Most Dangerous Animal of All” starts off in a frustrating manner, especially for those of us who know a great deal about this case, but eventually becomes a portrait of obsession and the true horror of that which we can never really know.

After humoring Stewart’s account, as well as synopsizing the Zodiac’s reign of terror, The Most Dangerous Animal of All surprisingly swerves in its final installment, pointing its inquisitive gaze squarely at Stewart himself. ... The sight of the once-confident and composed Stewart trying to defend his mistakes, and charade, is enlivening. Moreover, it turns the entire affair into a critique of both itself and, by extension, the true-crime genre, where sensational claims and pretzel-logic explanations are routinely, and easily, presented as trustworthy.

The Most Dangerous Animal Of All is intriguing enough to spend three-and-a-half hours on, but you may find yourself wondering why this story couldn’t have been told in half the time.

Director Kief Davidson allows the author to have his say and add new evidence that he's uncovered since the book's publication, but his team also does what Stewart's publisher, Harper Collins, apparently never did: fact-check his assertions. It's in those verifications that the documentary justifies its existence (though it never justifies its four-hour run time, which is stuffed with corny close-ups and recreations).

Those looking for well-earned emotion will find themselves satisfied, but crime junkies hoping the show will shed more light on the Zodiac will walk away disappointed.

The problem with The Most Dangerous Animal of All: Earl Van Best Jr. never comes into focus, and the Zodiac Killer doesn’t either. More importantly, the connection between Best and the monster who terrorized the Bay Area is woefully tenuous. ... The Most Dangerous Animal never really picks a lane, even with so many lanes available. It tries to do too much, and in some places with far too little.