A CBS News employee has been indicted in an alleged blackmail plot against David Letterman.
Manhattan District Attorney Robert Morgenthau announced the indictment Friday against Robert "Joe" Halderman.
Morgenthau says his office used an undercover sting operation to catch Halderman.
Letterman says he found a package of embarrassing e-mails and photos in his limousine.
His attorney took the evidence to the prosecutor's office office, which set up an undercover sting at a hotel.
New York police detectives were in an adjoining room with recording equipment and surveillance.
David Letterman acknowledged on Thursday's show that he had sexual relationships with female employees and that someone tried to extort him over the affairs.
During the taping of his CBS late-night show in New York, Letterman discussed receiving a threat to either pay $2 million or risk the relationships being made public.
In a release from the show's producer, Letterman said he referred the matter to the Manhattan district attorney's office and that an investigation ended in an arrest Thursday. Letterman did not identify the person he said was arrested.
As part of the case, Letterman said in a release that he testified before a grand jury and acknowledged sexual relationships with members of his staff.
CBS spokesman Chris Ender says "Letterman's comments on the broadcast tonight speak for themselves."