&gt; I&#x27;m torn. The part of me that believes in the right to a strong defense wants to assist, not necessarily because I support the defendant, but because the prosecutor shouldn&#x27;t be a rubber stamp. The other part is wondering what happens if I help defendant get off and he hurts someone else.<p>If the defendant has committed the crime, but the verdict is not guilty; then there was insufficient evidence to meet the burden of proof, and the system worked as designed. You have done your part as a defense expert witness to help the system work as designed. It may also be the case that the prosecutor does a poor job of presenting evidence, or law enforcement did a poor job of collecting or preserving evidence.<p>The goal of a criminal case is not to determine if a defendant is guilty or innocent or not guilty; it&#x27;s to determine if the evidence shows if the defendant is guilty, beyond any reasonable doubt, and if not, to acquit the defendant of the specific charges and leave the matter closed. It&#x27;s not quite the same. You don&#x27;t always get one of those results though, if you have a hung jury, or other exception.<p>Even if the defendant is guilty, he should have a strong defense -- the system (and the state) must be kept honest.