Actor Stephen Root is the latest to join the cast of Clint Eastwood's biopic J. Edgar, which is currently in production.

Stephen Root will play Arthur Koehler, a forensic wood specialist who helps J. Edgar Hoover (Leonardo DiCaprio) investigate the kidnapping of Charles A. Lindbergh's (Josh Lucas) son. Arthur Koehler aids the case by examining a ladder used by the abductor.

Clint Eastwood is directing J. Edgar from a script by Dustin Lance Black. A specific release date has not been announced yet.