It is hard to say with any certainty, especially since the heirs and beneficiaries are not going public explaining how they received their illegal proceeds.

Most guys try to launder some of their illegal proceeds into tangible assets during their lifetime. John Gotti Jr. owns several rental houses for example.

Often, illegal cash is used to buy gold and jewels, which are more easily stored than $2 or $3 million dollars in $10 and $20 bills. Gold and jewels can be transferred to heirs without a paper trail, and generally appreciate.