(a) It is an affirmative defense to prosecution under Section 71.02 that under circumstances manifesting a voluntary and complete renunciation of the actor's criminal objective, the actor withdrew from the combination before commission of an offense listed in Section 71.02(a) and took further affirmative action that prevented the commission of the offense.
(b) For the purposes of this section and Subsection (d) of Section 71.02, renunciation is not voluntary if it is motivated in whole or in part:
(1) by circumstances not present or apparent at the inception of the actor's course of conduct that increase the probability of detection or apprehension or that make more difficult the accomplishment of the objective; or
(2) by a decision to postpone the criminal conduct until another time or to transfer the criminal act to another but similar objective or victim.
(c) Evidence that the defendant withdrew from the combination before commission of an offense listed in Section 71.02(a) and made substantial effort to prevent the commission of an offense listed in Section 71.02(a) shall be admissible as mitigation at the hearing on punishment if the actor has been found guilty under Section 71.02, and in the event of a finding of renunciation under this subsection, the punishment shall be one grade lower than that provided under Section 71.02.