"A black man did it."

Hear that line, and watch Samuel L. Jackson, playing a do-gooder cop, shrink in his own skin. Lorenzo Council has fought the good fight and been a neighborhood peacekeeper for the troubled projects in fictional Dempsey, N.J.

But when he hears those awful words, connected to a car-jacking, he lets us see his heart break. It’s a tribute to Jackson, offering up his best, most engaged performance in a decade, that we share Lorenzo’s fears for what this accusation could mean, his compassion for the victim, and his doubts about her, all at once.

Freedomland is so well-acted, so poignantly written, that you can almost forget its excesses and shortcomings and embrace it for what it is – a serious writer’s exploration of racism, cop mob mentality and the mechanics of guilt.

Richard Price, adapting his own novel, comes at the case from an angle - giving a mother who says she’s lost her son to a car-jacker a match and a fuse to light with it, and a city that could explode if she isn’t validated or discredited.

A bloody, shocked woman – played by Julianne Moore – has staggered into a hospital. What happened to her? It’s Lorenzo’s job to find out.

"Brenda" doesn’t give up her secrets easily. She’s seriously out of it. We learn she used to be a junkie. But she’s clean, she says. She’s the sister of a cop from a neighboring (and whiter) city. And her work in a day-care center has made her a popular figure in those same projects.

Until, she says, a black man knocked her down and took her car. With her 4-year-old-son in it.

Jackson leaves it all on the court with this performance, an asthmatic detective who can’t keep a lid on her accusations or his doubts about them. The pose is gone, the Coach Carter strut. His sermonizing here is Price’s preaching, a man who has to find the kid, or get the mother to admit to killing him, before the racial tensions between police departments and a "lock-down" of an entire neighborhood blow up on him.

Moore has played this distraught mother before, but never with this wastrel’s edge. Edie Falco, setting herself up for a solid Frances McDormand/post-"Sopranos career," plays the leader of a volunteer group that searches for lost children.

Freedomland has the classic thriller’s "ticking clock," compelling characters and occasional bursts of urgency, as when Lorenzo first discovers there’s a child involved (an asthma attack kicks in). But it is never concerned enough with maintaining mystery. And it loses itself to too many "actor’s scenes" – long, literate monologues that play beautifully on the page but in a movie sound written, not thought of on the spot.

Jackson has wasted an awful lot of his career on movies that brought him closer to the right golf courses or the big checks. Yes, this is deep within his comfort zone. But it’s great to see him lose the strut, the pose and the too-cool preaching, and get – as Jules put it so perfectly in Pulp Fiction – his "game face on."

Grade: B