United States v. Richard Mathews, 2014 U.S. App. LEXIS 14762

Mathews operated multiple internet-based MLM businesses and questioned the government’s authority during prior IRS audits.
The 2007 IRS audit uncovered unreported income related to a PayPal account and an undisclosed business account.
During interviews, Mathews repeatedly altered key details about his operations and claimed one business was a Belize-trust beneficiary.
A 2009 search revealed cash in his home; Mathews initially denied ownership of some cash but later admitted it was his.
Bank records showed large gross receipts from 2004–2008, while his returns reported far smaller amounts, with him treating deposits as personal income.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Sufficiency of evidence for willful filing of false returns	Mathews argues no willfulness proven; no mental state shown.	Government proved a pattern of under-reporting and evasive conduct indicating willfulness.	Sufficient evidence supported willfulness; rational jury could convict.
Sufficiency of evidence for endeavoring to obstruct IRS	Mathews claims no intent to obstruct the administration of tax laws.	Mathews lied to IRS agents and concealed information to hinder enforcement for financial gain.	Sufficient evidence supported obstruction, rational jury could convict.

Cheek v. United States, 498 U.S. 192 (U.S. 1991) (willfulness requires voluntary violation of a known duty)
Morris, 723 F.3d 934 (8th Cir. 2013) (sufficiency de novo; credibility resolved in favor of jury)
Yarrington, 634 F.3d 440 (8th Cir. 2011) (pattern of conduct supports willfulness finding)
Ojeda-Estrada, 577 F.3d 871 (8th Cir. 2009) (credibility of witnesses resolved by jury)
Schaefer, 4 F.3d 679 (8th Cir. 1993) (conduct can prove willfulness)
Bliss, 735 F.2d 294 (8th Cir. 1984) (willfulness shown by concealment of transactions)
Dykstra, 991 F.2d 450 (8th Cir. 1993) (definition of 'corruptly' in § 7212)