Season 1, the Feds have Junior on tape talking about clipping Tony. Granted, the conversation is with Livia, but when you consider there was an attempt on Tony's life after that you would think the Feds had a pretty good murder conspiracy case.

Which begs the question, why didn't the Feds jam him up on a murder conspiracy? At the age of seventy, he would have been looking at the rest of his life in the can. He may have flipped.