What does his disability pension which he "earned" (an assumption!) before his conviction have to do with anything? If he pays the lottery and wins AFTER his conviction, could the state refuse him/his family his money? (assuming an inmate can play the lottery ...) If he had millions in bank accounts (minus any fines/leins for pain and suffering to his victims/thier families!) - could the state refuse him / his family this money?
Except of course unless you get pulled over on the interstate and you have too much cash on you, then that can be stolen, err, I mean seized without any such due process. One of the great benefits that the war on drugs has given us, that ol’ pesky constitution be damned.