Veteran radio DJ Dave Herman died while in federal custody in New Jersey on Thursday, officials said.
Herman, 78, started feeling chest pains Wednesday in the Essex County jail where he had been held since his October 2013 arrest.
He was taken to University Hospital in Newark and he died about 11 a.m. Thursday.
The former WNEW-FM disc jockey was arrested last year after he allegedly planned a sexual tryst with a 7-year-old girl, according to the New Jersey U.S. Attorney's office.
Herman initially started talking to a woman online who he believed to be the mother of the child -- but who was really an undercover officer from the Bergen County Prosecutor's Office, authorities said.
He was charged with attempting to transport a minor in interstate commerce with the intent that the minor engage in illegal sexual activity.
The circumstances surrounding his death are unclear and he is scheduled to undergo an autopsy Friday.