This comment got me laughing really hard, but since this is HN I'm going to try to figure out the answer anyway:
I think this scenario is pretty simple and is essentially just that you deduct the amount of money stolen from you from that year's income, provided you discovered the money was stolen that year. Obviously if you haven't discovered it's stolen yet you won't be deducting anything.
It seems that the tax evasion part essentially becomes totally irrelevant since, as others have said, you don't report evaded taxes as income, you just don't tell the IRS you owe those taxes and don't pay them, so from the IRS' perspective it's no different than you getting that quantity of non-evasion money stolen from you
I think this scenario is pretty simple and is essentially just that you deduct the amount of money stolen from you from that year's income, provided you discovered the money was stolen that year. Obviously if you haven't discovered it's stolen yet you won't be deducting anything.
It seems that the tax evasion part essentially becomes totally irrelevant since, as others have said, you don't report evaded taxes as income, you just don't tell the IRS you owe those taxes and don't pay them, so from the IRS' perspective it's no different than you getting that quantity of non-evasion money stolen from you