RSA 629:1 Attempt.

I. A person is guilty of an attempt to commit a crime if, with a purpose that a crime be committed, he does or omits to do anything which, under the circumstances as he believes them to be, is an act or omission constituting a substantial step toward the commission of the crime.
II. As used in this section, "substantial step" means conduct that is strongly corroborative of the actor's criminal purpose.
III. (a) It is an affirmative defense to prosecution under this section that the actor voluntarily renounces his criminal purpose by abandoning his effort to commit the crime or otherwise preventing its commission under circumstances manifesting a complete withdrawal of his criminal purpose.
(b) A renunciation is not "voluntary" if it is substantially motivated by ci