Iowa Code Title XVI. Criminal Law and Procedure [Chs. 687-916] § 816.3. Exceptions--limitation

1. By a former prosecution before a court which lacked jurisdiction over the defendant or the offense.

2. By a former prosecution procured by the defendant without the knowledge of a prosecuting officer authorized to commence a prosecution for the maximum offense which might have been charged on the facts known to the defendant, and with the purpose of avoiding the sentence which otherwise might be imposed.

3. If subsequent proceedings resulted in the invalidation, setting aside, reversal or vacating of the conviction, unless the defendant was adjudged not guilty; but in no case where a conviction for a lesser included crime has been invalidated, set aside, reversed or vacated shall the defendant be subsequently prosecuted for a higher degree of the crime for which the defendant was originally convicted.