I believe you're trying to ask an immigration. Specifically, whether you are entitled to a U visa because of the malicious prosecution by an ex-girlfriend. Getting the question correctly framed is almost as important as the answer. Speak privately with an immigration attorney in your area for a definitive answer.
The answer provided is for general information purposes and cannot be relied upon. In order to provide legal advice, one must engage with a live attorney; this answer does not create such attorney-client relationship.
While I think it is safe to say that the false charges that resulted findings of not guilty and Nole Prosequi should not interfere with your qualification for a U visa, you need to address these issues with an immigration attorney.