Samuel Witwer's middle name is of Russian origin.
Samuel Stewart `` Sam '' Witwer ( born October 20 , 1977 ) is an American actor and musician . Stewart is a Scottish surname ( also used as a masculine given name ) possibly of pre-7th century Old English origin , derived from stigeweard , the genitive prefix stige meaning `` hall '' , and the suffix weard meaning `` guardian '' or `` warden '' .