You need to read up more on Mafia in that time period. Where did you come up with them getting off for 99% of crimes?
I was talking about bosses. Yonnie Licavoli, Vito Genovese and Lucky Luciano were the only ones to have done serious time before RICO was made. Some capos went to jail, but I thought it's generally considered that the first serious blow against the de-facto national leadership of the mafia came with the Commission trial in the 80s.