If the son of the Vice President received large sums of money that the Treasury Department determined was laundered through shell companies to hide its illegal origin this is a crime. It falls under the RICO statutes. If he failed to report this income that adds tax evasion to the charges.
The relevant question is what Joe knew about these criminal activities and when he knew it. If he had knowledge of criminal behavior he is obligated to report it to law enforcement or he can be charged with obstruction of justice as a sworn official under the constitution.
If Joe had any knowledge of it it’s lost in the oatmeal soup he calls a brain now.
If Joe had knowledge? He’s on videotape committing extortion, related to this deal.