Legal Question in Criminal Law in California

I'm not sure what you want us to tell you. A short curt or sarcastic answer would not help you.

It appears a woman filed charges against him, the police and prosecutor's office believed there was some evidence [victim testimony] of a crime and identification of the culprit, a criminal case was filed, investigation by defense and prosecution resulted in the prosecutor's conclusion that they couldn't sufficiently prove the case on witness testimony alone, and the case was dismissed 'in the interests of justice'. You are fortunate, as sometimes these case are 'forced' into a plea deal on threat of a trial, even with weak evidence, instead of a dismissal.

Is it 'legal'? You haven't said anything that would indicate this is any different from a majority of criminal cases that are based upon victim complaints of conduct that occurred outside the direct view of police. The fault, if any, is that the victim and prosecutor's office couldn't credibly corroborate her story. The delay and hassle is typical of high workload prosecutors and public defenders and an over-crowded court docket. Private counsel could possibly have accomplished this faster. The dismissal seems to be confirmation that the prosecutor's office was acting ethically under the later discovered circumstances of a failure of evidence.

'False charges'? Maybe, maybe not. Whichever it is, all such reporting of crimes, and testimony in court proceedings, is "protected" and "privileged". That means that a complaining victim or witness can not be 'sued' for what was reported or said to police or in court. If the Court found the witness to have significantly knowingly lied, charges of false police report or even perjury could be brought against them by the prosecutor at the court's direction.

Also, the prosecutor's office is 'immune' and protected from suit as well, unless you can credibly PROVE that they KNEW the charges were false and conspired with the victim to bring knowingly false charges. Just because you denied them, and the charges were found later to be unprovable, does not retroactively make them 'knowingly false' as to the prosecutor or the victim.

This sounds like a common basis for charges of 'date rape', that started for the purpose of strangers 'hooking up', with the woman changing her mind later about how voluntary was her participation, frequently under the influence of alcohol or 'self medication'. I suspect that without the tapes, the outcome would have been dramatically less favorable to your son. Many men are in prison right now, based upon a woman's uncorroborated testimony that was believed by a jury.

The lesson here should be for everyone to make better choices of partners and behavior, so police and prosecutors don't become involved. If they do, hire private counsel next time. Feel free to contact me then.