Iowa Code § 705.2

It is a defense to a prosecution for solicitation that the defendant, after soliciting another person to commit a felony or aggravated misdemeanor, persuaded the person not to do so or otherwise prevented the commission of the offense, under circumstances manifesting a complete and voluntary renunciation of the defendant’s criminal intent. A renunciation is not “voluntary and complete” if it is motivated in whole or in part by (a) the person’s belief that circumstances exist which increase the possibility of detection or apprehension of the defendant or another or which make more difficult the consummation of the offense or (b) the person’s decision to postpone the offense until another time or to substitute another victim or another but similar objective.