http://www.thesmokinggun.com/file/sammy-bull-gravano-fbi-debriefings?page=31

Gravano named all the players in the Castellano hit. Pretty sure they were never charged though.

I may be forgetting some crucial piece of evidence, but I'm not sure how they were able to convict Gotti of the Castellano shooting. The only thing they had is Gravano's testimony. Gotti even denies doing it on the tapes.