"However, it is an idiosyncrasy of our federal criminal justice system (codified in rule 12(b)(3) of the Federal Rules Of Criminal Procedure) that unless the accused demurs to an indictment for failing to allege an essential element of an offense in a preliminary hearing, the prosecution is excused from an obligation to prove the truth of that specific element during trial. Challenge regarding any such defect, if not made upon presentation of the indictment (or by way of motion for a bill of particulars within 10 days or arraignment), is deemed to be waived. Only challenges to jurisdiction, or an outright failure to allege an offense, must be subsequently entertained by the court; and only the elements alleged in the final indictment must be proven at trial.
For instance, consider a hang-glider charged with flying below an altitude of 100 ft. and thus violating a law against such behavior. If he allows the matter to go to trial with such an indictment left unchallenged, the prosecution will be obliged to prove only that he was indeed flying below 100 feet. If this is proven, the hang-glider can expect to be convicted. If, however, the hang-glider challenges the indictment, pointing out that the authority under which the law in question is promulgated is confined in its application to powered aircraft, he can then oblige the prosecution to include, as an essential element of the offense, that he was flying below 100 ft. AND that he was doing so in a powered craft. Now, the prosecution must prove BOTH elements of the offense during the trial.
Sadly, it appears that Irwin and his associates left the indictment's defects as to their receipt of "income" unchallenged. Although the memoranda of law Irwin posted suggest that his motion to dismiss did seek to contest the government's presumptions as to his liability for a tax on the "income" that he was alleged to have received (along with a few other things), these are losing arguments if his receipt of "income" above a threshold amount is left to stand as a given, and it seems clear form the court's instructions to the jury that this was the case. "
For more, see:
http://www.losthorizons.com/tax/Misunderstandings/TheSchiffTrial.htm
