And I am 18 years of age or older. An affidavit of nonprosecution is a sworn document in which the plaintiff expresses their desire not to prosecute the case or participate in the prosecution.How do i go about filling out an affidavit of non prosecution? Is there a form i can fill out or a certain wording required? Filling out an affidavit of non-prosecution in Texas is pretty straight-forward. It should state that the victim doesn't want to cooperate or prosecute. How to file an affidavit of non prosecution in Texas? It's usually best to give this to your ex partners Defense attorney. That way, the attorney can offer that to the State when the time is right. An affidavit of non-prosecution is not a "special" form.