For those audience members who have read Truman Capote's "In Cold Blood" or at least seen the 1967 film of the same name, "Capote" will make for a fascinating, enriching companion piece. For those less familiar with the case of Perry Smith and Richard Hickock, who in November of 1959 murdered a family of four in a Kansas farmhouse, "Capote" will not be terribly enlightening on its own, but will make them want to seek out the source material to get a fuller view of the crime. Even when the literate and low-key screenplay by Dan Futterman doesn't delve as deeply into the particulars of eccentric "In Cold Blood" author Truman Capote's life and investigation as desired, Philip Seymour Hoffman (2004's "Along Came Polly"), in the title role, makes the journey worthwhile. This is an amazing performance—transformative, exquisitely modulated, climbing tricky heights as he moves between sympathetic, ruthless and narcissistic—and Hoffman's completely convincing portrayal allows him to so indelibly embody the part that the actor seemingly disappears for 98 minutes.

A biopic of Truman Capote centering almost entirely on his research into the Clutter Family murders as he works on a non-fiction novel about the crime, "Capote" director Bennett Miller sucks the viewer immediately into Capote's world and investigative process, even as he sometimes neglects to three-dimensionalize these very things. Choosing Nelle Harper Lee (Catherine Keener), future novelist of "To Kill a Mockingbird," as his research assistant, Truman and she first travel to Kansas to visit the crime scene, work their way into the good graces of area police chief Alvin Dewey (Chris Cooper) in exchange for information on the case, and interview 16-year-old Laura Kinney (Allie Mickelson), who made the grisly discovery of the bodies. In an attempt to learn more about the killers, Truman also visits killers Perry Smith (Clifton Collins Jr.) and Richard Hickock (Mark Pellegrino) on death row, and is surprised to find humanity within their characters. Torn between his devotion to his writing and the burgeoning personal stake he has in these criminals, Truman's writing of their story, titled "In Cold Blood," excels. However, with their fates up in the air—they receive numerous stays of executions and appeals over three-plus years—Truman is frustratingly left without an ending to his book.

Despite almost being driven mad by his research and ill-fated friendships with the killers—and consequently never penning another book—"In Cold Blood" single-handedly marked Truman Capote's place in the history books and was cause for his being hailed as one of America's greatest writers. "Capote" could have benefited from a clearer look at this figure from a writing standpoint—our one glance at his prose when he gives a reading from his unfinished work is over way too soon to make the intended impact—but is captivating when dealing with the lengths Truman will go to get his story. There is an intriguing tug-of-war that Truman goes through—he becomes emotionally invested in Perry and Richard, even as he willingly lies to their faces to retain their trust—that offers the most valuable glimpse into his helplessly self-absorbed personality.

This is cemented further in his friendship with Nelle Harper Lee, who devotes herself to his work but learns quickly not to expect anything in return. Indeed, when it is time for her moment in the spotlight at the movie premiere of "To Kill a Mockingbird," Truman doesn't stop lamenting about his own troubles long enough to even acknowledge her achievements. As Lee, Catherine Keener (2005's "The 40-Year-Old Virgin") proves an excellent foil for Truman, holding him up when he needs it and poignantly expressing in slyly subtle ways her realization that he is incapable of sacrificing a part of himself, if even for a minute, when it doesn't relate to personal gain.

As the offbeat Truman Capote, who made do with his curious voice and homosexuality in the 1950s and '60s by being a great storyteller and well-liked socialite, Philip Seymour Hoffman takes a historical figure whose voice and personality could have easily gone the way of caricature and avoids such trappings. Hoffman is Oscar-bound in this role, broad only when the script calls for it and really giving life to the dilemma he faces between wanting to help the convicted killers and wishing for the worst in the name of improving his book's content. It is one of the year's strongest turns, and the main reason to seek out the picture in spite of its shortcomings.

As a biopic, "Capote" is too sketchy in the details of Truman's past and background, and as a study of the crime and suspects that inspired "In Cold Blood," it isn't thorough enough to have the immediate impact it should. Furthermore, the unfortunate victims involved in the case never grow beyond plot devices, rather than people worth feeling anything for. What does make an impression, then, is not only Philip Seymour Hoffman's marvelous performance, but director Bennett Miller's provocative consideration into the internal conflicts of a writer haunted by his purely self-centered drive for attention and success. Truman recognizes this, but cannot stop it, and Miller suggests that his inability to allow human compassion into his life as a writer was the reason he never completed another book. "Capote" could have used a fuller exploration into its subject matter, but what is there is still interesting and thoughtful enough to be a fine introduction to the more in-depth "In Cold Blood."