Based on the popular comic book series of the same name, the movie, set in a future where police act as judge, jury and executioner, focuses on Joe Dredd (Urban), a member of this elite corps. Thirlby will play Cassandra Anderson, the telepathic rookie who shadows Dredd.
Thirlby starred in Farragut North at both New York's Atlantic Theatre and the Geffen Playhouse in Los Angeles. Her film and television credits include Juno, United 93. The Answer Man, and Bored to Death.