Warren Brown (born 11 May 1978) is an English actor and former professional Thai boxer, best known for his roles as Donny Maguire in Shameless and Andy Holt in Hollyoaks, DS Justin Ripley in acclaimed BBC crime drama Luther and as Sergeant Thomas "Mac" McAllister in Retribution, the British-American action television series, which is the sixth series and second revamp of Strike Back.