Taxes on Bribe Money?

Duke nuked By Alexander�Dryer

I love the government's sentence of Duke Cunningham for bribery. Not only does he go to jail for 8 years and 4 months, he has to pay $3.5 million in "penalties, restitution, and back taxes." It's the back taxes part that really pleases me: essentially all his bribe money (which he has to pay back) was also undeclared income which means he never paid taxes on it. He now has to pay taxes, interest and penalties on all of that money. That's like getting punished twice for the same crime - which he deserves for betraying the public trust.