Contrary to what some of you are saying, I think Hank was very smart....
I LOVE THIS MOVIE, one of my favorite thrillers...
I've enjoyed reading the forums....but I have to disagree with some of you who say Hank was just an average, not-so-bright blue collar guy....
I definitely agree that there are ways to launder money (Better call Saul!!!), and he should have thought it through....but basically I think the reason he burned it was because he was in shock/anger/denial/etc. (he did kill his brother and cause four other murders) and was just OVER IT. By then he was probably so tormented, traumatized, etc. that he figured there was just no way out and that it needed to end. That was his only way out.
Granted, he wasn't a super sophisticated guy, but I think he was plenty smart.
So was his wife.
The rest of the people in the movie were dumb as rocks.