Justin was born and raised in Washington, D.C, and graduated from Bennington College with a bachelor of arts degree. He then moved to New York to pursue a career in the visual arts, but soon found himself immersed in stage acting. He starred in numerous off Broadway plays before his feature film career began. He currently lives in New York.
Nephew of Paul Theroux, author of many travel books. Cousin is Louis Theroux, actor, writer and journalist who makes television programmes for the BBC. Appears in the "Mafia" episode of the Comedy Central show Upright Citizens Brigade. He is filmed talking to one of the actors during a hidden camera skit that was filmed in a dog park in New York City. Have be seen wearing the same black glasses he wore in Mulholland Dr.. Starred in rock band Muse's film clip "Hysteria." Has a younger brother, Sebastian, born in 1989