‘Conviction’ role fits Swank

Hilary Swank is at her best in working-class, little-people roles, and she’s found another one with “Conviction.”

It’s the real-life story of Betty Anne Waters, who put herself through law school during an 18-year fight to clear her brother of a murder rap.

The drama is straightforward, even a bit superficial, kind of an “Erin Brockovich” on a bad-hair day – still appealing and inspiring, still ready to take on the system, though rote and predictable here and there.

But Swank, sometimes adrift in lofty parts such as Amelia Earhart in last year’s “Amelia,” keeps “Conviction” grounded with blue-collar pluck and earnestness reminiscent of her Oscar-winning roles in “Boys Don’t Cry” and “Million Dollar Baby.”

She’s nicely aided by excellent performances from Sam Rockwell as Waters’ brother, Kenny, and Minnie Driver as a lawyer pal who joins the effort to free him.

Director Tony Goldwyn and screenwriter Pamela Gray, who previously collaborated on “A Walk on the Moon,” offer flashbacks to show the deep bond between Betty Anne and Kenny, their attachment unshakable despite a hard-knocks childhood in which they were sometimes separated in different foster homes.

While touching, the childhood moments pile up a bit too thickly, bogging down the main event.

That begins with the 1980 stabbing death of a Massachusetts woman in a robbery at her trailer home. Kenny initially is questioned and released, but three years later, he’s sentenced to life in prison, partly on testimony from two ex-girlfriends (one played by Juliette Lewis in a small but effective role).

With the judicial system shrugging off his pleas of innocence, Betty Anne, who has two kids to tend and doesn’t even have a high school diploma, embarks on the long process of getting an education and a law degree in hopes of springing her brother from prison.

Along with Driver, she finds help from attorney Barry Scheck (Peter Gallagher) of the Innocence Project, which pioneered the use of DNA evidence to overturn wrongful convictions.

The action flows with a certainty that saps some of the drama and suspense. While Betty Anne continually hits what seem like insurmountable obstacles, there’s little doubt that she’ll find her way over, under or through each one.

Yet it’s enormous fun to watch Swank in her element, pounding down legal barriers with the same tenacity she used to knock out opponents in “Million Dollar Baby.”

When she lands the right part, Swank delivers with as much conviction as anyone working in Hollywood today.