A prosecutor is not permitted to charge a defendant with a crime when the prosecutor knows he or she does not have any evidence to prove the crime, but he can bring a charge that he knows is weak in order to get the defendant to plead to a lesser offense. For example, a prosecutor might have a good faith basis to charge someone with first degree murder, but have some doubt about being able to convince a jury beyond a reasonable doubt. In that case, the prosecutor can charge the defendant with first degree murder in order to get leverage to get the defendant to plead to second degree murder, manslaughter, or some other lesser offense.

In this case, the prosecutors are alleged to have known that they can't prove the knowledge element of the stolen identity statute. If that's true, then it is unethical for them to bring that charge, IMHO.