Suspect In Letterman Extortion Case

This is the man arrested for the $2 million extortion plot against David Letterman.

Robert "Joe" Halderman -- a well-respected producer for "48 Hours" -- was busted outside CBS headquarters in NYC for attempted grand larceny in the first degree.

Until recently Halderman was living with Stephanie Birkitt, Letterman's former assistant. We're told Letterman was having a relationship with Birkitt but ended it before his son was born in 2003.