Hillary Swank is the perfect star to play underdog crusaders of justice. Her blend of country-bred virtue and cutting intelligence is recognized by Conviction, but the movie is too constrained to give into needed dramatic payoffs. Recounting the true story of Betty Anne Waters---a Massachusetts mother who goes through law school in hope of exonerating her brother Kenny (Sam Rockwell) of a murder charge---the film has the hook of a sibling love story. But director Tony Goldwyn's TV-adequate filmmaking and Pamela Gray's faux-emotive script keep out needed poetry and thematic confidence. Things improve after the timeline-fracured first half, yet Betty Anne's mission isn't observed with the personal feeling to make it count. Like its silly double-meaning title, Conviction is half-hearted in all but its attempt to look serious.