Sam Rockwell has signed on for Betty Anne Waters, poised to join Hilary Swank in the Tony Goldwyn-directed legal drama for Omega Entertainment.

According to The Hollywood Reporter, Minnie Driver also has a role in the movie, which is based on the true story of Waters (Swank), an unemployed single mother who saw her brother convicted for a murder-robbery in 1983 and sentenced to life in prison. Convinced of his innocence, she spent the next decade earning a law degree and working on her brother's case. Rockwell plays the brother.

Richard LaGravenese wrote the most recent draft. Pamela Gray penned the original script.

Andrew Sugerman, Andrew Karsch and Goldwyn are producing, and Swank is exec producing.

Production begins this month.