The cautious new thriller “Murder by Numbers” does not try to impress its audience with snappy pacing and shocking twists. Like the title suggests, it is a methodical examination of murder, mystery, and clever forensic revelations. What the title does not reveal is the surprisingly tactful manner with which the film uncovers emotional secrets, examines devious manipulations, and displays psychological repressions. By avoiding the current trend of employing snazzy endings to compensate for silly screenplays, this Sandra Bullock vehicle is the smartest suspense flick so far this year.

In any case, director Barbet Schroeder needs no surprise finale, as the audience knows who the killers are from the film’s first frame. As a result, we are spared the incredibly overplayed “whodunit” format that became passe the minute “Scream” used it as a pop-culture joke. Instead, the film builds suspense by exploring how they did it, why they did it, and how they deal with its consequences.

The “they” in this synopsis are Richard Haywood (Ryan Gosling) and Justin Pendleton (Michael Pitt), two seniors in a San Diego high school who invoke the demented principle that “every truly free act is a crime” to justify their disturbing scheme to commit the perfect murder. Richard is the quintessential golden boy: the rich, popular, witty, intelligent, good-looking narcissist who can manipulate anyone simply by flattering him or her with his attentions.

Justin is the exact opposite: he’s a smart, introspective loner who hides his tortured isolation behind a quiet demeanor. Both boys are cliche high school foils, yet the film’s central tension and intriguing driving force is the way in which they come together to satiate their murderous needs.

While the teens plan and execute their perfect crime, smugly assuming they will get away with it, they underestimate the brilliance of tough, young detective Cassie Meriwether (Sandra Bullock) who smells trouble and almost immediately suspects the boys. As she and her partner Sam (Ben Chaplin) investigate and unravel the twisted murder, she simultaneously confronts her personal demon–a painful past that closely mirrors Richard’s and Justin’s strange relationship.

“Murder by Numbers” has plenty of flaws: the action lags at key moments, and supporting male love interest Ben Chaplin gives a mind-numbingly boring performance, displaying about as much pizzazz as Al Gore reading the dictionary. Luckily, he is an inconsequential character; the film relies mostly on Bullock and the murderous teens.

The homicidal relationship between these youths gives the movie its juiciest material. Gosling and Pitt create one of the most complex displays of teen angst in quite some time. What makes their actions so fascinating, in a post-Columbine world, is the way they defy the stereotypical explanation of such drastic measures without being unrealistic: they are not outcasts seeking revenge; instead, Justin touchingly seeks some sort of bond with Richard, while Richard wants to reassert his superiority on a riskier level. Their rendezvous in an isolated, cliff-side house are creepy because of the incompatibility in their friendship that they both find so seductive.

Both young actors give stunning performances. The film never really investigates the motives inspiring the murder, yet the acting is so convincing that one never needs nor really wants a traditional “murder-mystery” explanation. Gosling is the standout: he exudes a rare intensity that allows him to be both appealing and terrifying at the same moment. It’s a performance that brilliantly twists the emotional harm the “popular boy” can cause to his peers simply by appearing blessed, giving it a dangerous, palpable edge.

While these two up-and-coming talents clearly own the film, one cannot ignore the wonderfully consistent Bullock. Whether she is in a thriller, an action-adventure flick, or a romantic comedy, she is always reliably goofy, tough, and vulnerable. She has yet to give that one great performance I know she has in her, yet she holds “Murder” together with street-smart tomboy personality and her funny, flirtatious energy. She also does a nice job of incorporating her character’s past into her obsession with her current case while not turning her sob story into cornball melodrama.

“Murder By Numbers” may be by the numbers in terms of its many traditional murder movie elements, but it is the way it draws its suspense from the characters’ complexities that makes it fresh and fulfilling. Instead of pumping all its tautness into an overblown, wham-bam finale, it filters its thrills into each frame with intent and consequence.