John Rosenfeld is an American actor and acting coach. His most prominent role, as of 2007 is as Koren in the short lived CBS drama series Citizen Baines in 2001. Rosenfeld began his screen acting career in the late 1990s, appearing in short films and independent movies. In 1999 he got a role in an episode of ER, and during the 2000s he has appeared in episodes of several television series, including, among others, Buffy the Vampire Slayer, Star Trek: Enterprise, CSI: Crime Scene Investigation, Navy CIS, where he played FBI Special Agent Charles who was later turned into a mole by a Mafia Crime Boss and then ended up being killed in the Season 2 episode, "The Bone Yard", Charmed, How I Met Your Mother and Desperate Housewives. In 2003 he appeared in feature film Bruce Almighty, starring Jim Carrey.