Conversation so far:
What was Henry Hill arrested for?
On April 27, 1980, Henry Hill was arrested on a narcotics-trafficking charge.
What was Henry Hill selling?
Henry Hill sold marijuana, cocaine, heroin, and quaaludes based on connections he made in prison.
Did Henry Hill go to jail?
Henry Hill never went to jail, but he did go to prison.
Where was Henry Hill arrested?
Henry Hill was arrested in Washington, Florida, Illinois, and other locations.
What did Edward McDonald want with Henry Hill?
Edward McDonald wanted Henry Hill to be an informant.
Was any one else arrested at the same time as Henry Hill?
James Burke was also arrested with Henry Hill.

Question: Did they know it was him that snitched?
Self-contained rewrite: Did they know it was Henry Hill that snitched?