Truman Capote, famous for his books “Breakfast at Tiffany’s” and “In Cold Blood”, his drinking and his vanity, gets a troubling examination in Bennett Miller’s rich drama “Capote.” A Faustian tale sans moralizing, the film tells the story of a man out of touch with his humanity, a state which, as in “Citizen Kane,” leads to a tragic downfall. Rather than summarize the author’s life, Miller chronicles the six-year span in which Capote researched and wrote his masterpiece “In Cold Blood.” Just like his meticulously crafted book, “Capote” tells it like it is, sparing the heroic gloss which has become a staple in other biopics.

In 1959, Truman Capote (Phillip Seymour Hoffman) is riding the success of his hit novel “Breakfast at Tiffany’s” when he reads an article about a mass murder in a small Kansas town. Compelled by a mysterious need, he decides to travel to Kansas to write an in-depth piece for the “New Yorker.” He invites the then-unknown Nelle Harper Lee (Catherine Keener) with him.

Capote, with his high-pitched Southern drawl and effeminate mannerisms, isn’t trusted in Holcomb, Kansas. But gentle and likeable Harper Lee coaxes the townspeople to talk. As Capote learns more about the murder victims he decides to scrap the article and write a book instead.

When the killers are caught and turn out to be two men, Capote, a homosexual, develops a fascination with the more feminine of the two, Perry Smith (Clifton Collins Jr.). At first Capote identifies with him as a radical, as someone outside of society who needs a voice. But in a selfish drive to publish something so shocking it will impress his New York literati friends, his portrayal of Perry turns into something quite different. Given the choice between his ambition to write a sensationalist “non-fiction” novel about the killers and his desire to save Perry, Capote makes what seems like an easy decision, not realizing the ramifications it will have on his psyche.

Miller directs just like Capote writes, detailing gripping factual events with beautiful clarity and leaving out any analysis. This approach works for the plot. By focusing on the murder story and avoiding anything like a biography, the film blends the allure of nonfiction with the excitement of narrative. But Capote himself remains maddeningly enigmatic.

This is no fault of the acting which is, of course, first-rate. Hoffman loses himself completely in Capote, shrinking his hulking form into the author’s diminutive posture. He gets everything right, from his physical twitches to the position of his cigarette hand, yet manages not to mechanize the role. His Capote feels impromptu and real.

Newcomer Clifton Collins Jr. matches him as the murderer Perry Smith, in a less-strenuous yet equally-intense performance. Tough and hypnotically empathetic, Perry manages to garner trust while remaining dangerously elusive. Collins Jr. incarnates the part right out of the pages of “In Cold Blood.” Rarely does a book’s description of a character so closely fit an acted performance.

Filling the middle ground, Chris Cooper’s Sheriff Alvin Dewey, who is investigating the Holcomb murders, is dignified and warmly Midwestern. For the part of Harper Lee, Keener abandons the icy demeanor of her “Malkovich” days and instead plays a pseudo-conscience for Truman with motherly charm. The chemistry between the gentle Lee and effeminate Capote is both wonderful and human.

But, for the most part, empathy and emotions are unreliable in “Capote.” Truman purports to have intense feelings for Perry Smith, but he lies to him about the contents of his book. Perry seems to be all sweetness, but he murdered an innocent family of four. The movie avoids pat explanations for these personality shifts, showing that mere facts can’t explain the deep secrets of the psyche. It seems the more we see in “Capote,” the less we know.

The prison scenes between Capote and Perry are the canvas for the film’s most compelling visuals and puzzling conversations. Shot in intense close-ups which slip in and out of focus, they have the unsettling, nostalgic effect of a fever dream. Cinematographer Adam Kimmel captures every facial tick, suggesting the possibility of a revelation but, ultimately, telling us nothing about the two enigmatic masterminds filling his frames. Kimmel does for these interviews what Vittorio Storaro (“Apocalypse Now”) did for jungle warfare — he hides the truth through plain sight.

At times poignantly true and always deeply disturbing, “Capote” is about what happens to someone who sacrifices his humanity for a bestseller. In the end, Capote out manipulates the manipulator, wresting the last details of the murders from Perry before his execution. But his passionless journalism crossed a line — Truman Capote never wrote another book and died from alcoholism twenty years later.

“Capote” shows his life with the meticulous eye of a reporter and the zeal of an entertainer, but restrains its desire to play psychologist. True to life, “why?” remains the final piece in the jigsaw puzzle — the missing piece.