Violating company policy should be grounds for dismissal, not criminal prosecution. If you venture into criminal behavior *during* your misuse of computer systems, you should be prosecuted, but not for the misuse itself.
This is a stinky case of fruit of the poison tree. Regardless of whether specific officers felt they were acting in good faith, the warrant execution was illegal, and the Stingray findings are fruit of the poison tree.
I wonder if California has any regulatory limits on how long documents created with public funding must be retained. Certainly the School Board can't make the retention period less than any state requirement?