Brown played a recurring character on the television series '' Supernatural '' , where he portrayed vampire hunter Gordon Walker . Brown played Dr. Roland Burton on '' Army Wives '' . He portrayed Detective Cal Beecher on '' Person of Interest '' , also appearing on the show '' Medium '' . In 2008 , he played David Mosley on the " Patience " episode of '' Eli Stone '' . In 2016 , Brown starred in the FX miniseries '' The People v. O.J. Simpson : American Crime Story '' as Christopher Darden , for which he won the Primetime Emmy Award for Outstanding Supporting Actor in a Limited Series or Movie at the 68th Primetime Emmy Awards
68th Primetime Emmy Awards
68th Primetime Emmy Awards
Sterling K. Brown