It's not the *heirs* that would be sued in civil court,it's the *estate*.Unless I'm mistaken,the probate laws of every state in the union require the executor of an estate to settle all debts incurred by the deceased during his/her lifetime before distributing proceeds to any heir.
Also,was his wife also convicted of one or more crimes in this matter? If so...and if any substantial portion of his estate was given to the wife in a will,then one would think that *she*,too,could be pursued in civil court.
I'm certainly no lawyer,so I'm probably in way over my head here.
However, future civil suits would take place after Lay's death. If he hasn't been sued by now, then there aren't any debts incurred for which to sue the estate.