No wonder you got nowhere.
You don't take a case to a DA. If the DA hasn't come looking for you (usually due to publicity), then don't bother.
What you do is counter-sue the employee for fraud. Your "well documented case" is your ticket to getting a bigger settlement from your employee than what you stand to lose to your employee in her original suit against you.
But here's the kicker: in your counter suit, any decent attorney will set up the case so as to provide you with an opportunity to ask the judge in your *civil* case to order the employee held on *criminal* charges.
You tried a full frontal attack (by going to the DA). You lost. I've been in business for decades. I seldom go for full frontal attacks. Far more successful are the oblique attacks. Let the judge demand charges. DA's don't turn judges down.
You'll learn.