Like a fly zapper, the front door light flickers. Mrs. Fitzgerald sighs and stands on her tip-toes to change the bulb. The first thing she sees on the newly lit cement is a bloodstain.

“I think, uh, I made a mistake,” Leland Fitzgerald (Ryan Gosling) tells his mother when she finds him upstairs with a bloody hand. After fatally stabbing the mentally disabled brother of his ex-girlfriend (Jena Malone), this remark in The United States of Leland may be the understatement of the year.

Leland is then convicted and sent to a juvenile detention center, but director Matthew Hoge leaves it up to the audience to decide if Leland’s actions were justified.

The crosswire of contradictions are designed to get the brain ticking, but the movie isn’t a drone of intellectual jargon. Though not a speedy thriller, Leland does have its share of twists and turns.

Sweet, childlike Leland seems to have gone crazy on his harmless schoolmate for no reason. Or maybe it’s all a façade, and Leland is just a really calm psychopath.

Either way, Gosling makes his character likeable because he’s a natural at playing the nice guy role.

As Leland begins to interact with Pearl Madison (Don Cheadle), an aspiring writer and a teacher in the detention center, Leland’s mindset becomes clearer.

Leland turns the tables on Madison’s interrogation, and the teacher finds he has some explaining to do about infidelity. Cheadle’s emotional struggle is convincing, and his stuttering comeback of “Everybody makes mistakes” and “I’m only human” shows that doing wrong matters far more than the degree of wrongdoing. Madison’s affair and Leland’s murderous act are put on the same level.

It’s a complicated plot, but a tight cast and strong acting by Gosling and Cheadle pull this film together. An appearance by Chris Klein as the usual soft-spoken jock is a bit disappointing, but the rest of the acting, including a surprisingly honest performance by Michelle Williams, aims to please.

There’s plenty of humanity woven into this insightful flick, which makes for easy and thoughtful viewing.

But even if you don’t appreciate Leland’s efforts to shake a disapproving finger, it will at least guilt trip you into being good for a few days.