Even the casual layman can see that Casso is mentally deranged and would be a liability, whether on the stand or back on the street.

And it wasn't the Feds who f***ed over his family after he went to prison. That would have been his buddies extorting his wife (something they would've been too chickenshit to do if he was still on the street) and Burton Kaplan screwing him over on the rights to his mansion in Mill Basin.

Mobsters get it pretty good from the government IMO. Look at Joe Massino.

Gets to keep virtually all his money - not a cent of which was earned legally, and his wife/children don't have to worry about working an honest job; something which seems like an alien concept to them.

Less mobsters would rat to begin with if they would stick to their oath and take care of each others families when they go to the joint.

I invoke my right under the 5th amendment of the United States constitution and decline to answer the question.