Mark Andreas Sheppard (born 30 May 1964) is a naturalized American and musician, born in London, England of an Irish-German background. He is often credited as "Mark A. Sheppard". Sheppard is best known for his recurring roles as the King of Hell Crowley on Supernatural, lawyer Romo Lampkin on the Battlestar Galactica reboot, Interpol investigator James Sterling on Leverage and small-time crime lord Badger on Joss Whedon's Firefly.