Most criminal tax cases start with civil audits.
Per Title 26 §7203 Any person required under this title to pay any estimated tax or tax, or required by this title or by regulations made under authority thereof to make a return, keep any records, or supply any information, who willfully fails to pay such estimated tax or tax, make such return, keep such records, or supply such information, at the time or times required by law or regulations, shall, in addition to other penalties provided by law, be guilty of a misdemeanor and, upon conviction thereof:
The elements Necessary for Prosecution:
(2) Requirement to file a return, pay an estimated tax or tax, maintain records, or supply information
(3) Failure to file a return, pay an estimated tax or tax, maintain records, or supply information