> So IRS is just gonna accept that you made $241,000 and just that dealing drugs
No, they are going to accept that you made $241,000 in regular income from sources that do not provide W-2s, 1099s, etc. The “dealing drugs” part is not part of the filing.
> Tax return is step one, if red flags are raised, it's audit time with explanations, witnesses, ledgers etc.
Red flags are more likely to be raised by living beyond the means suggested by your reported income as by reporting income with no apparent source; IRS audits and investigations are looking for evidence of concealed income or other evasion of tax liability, not satisfying curiosity about the sources of reported income otherwise, and the Fifth Amendment right against self-incrimination applies.
It's true that laundering money so that you can avoid both reported income with no apparent source and living beyond the means of your reported income is a common technique (though still technically usually tax evasion, since it usually involves concealing some part of the gross income which is expended in the scheme, and that income is taxable and you cannot deduct illegal expenses against illegal income, so the cost of laundering is not deductible.)
> No doubt in my mind that agencies talk to each other, formally or informally.
Well, they certainly coordinate in the direction that gets criminals who conceal the details of their other crimes well enough to complicate prosecution but evade taxation busted for the tax offenses. The direction you are concerned about is less evident, though.