What can I do if I have an open case that I wasn't aware of until I was pulled over for speeding?

I have been living in California for the past few years since 1999. I left New York and recently came back earlier this year (2014). I was pulled over by Nassau Police due to speeding and told I had a case open in court and active warrant in Nassau for a NY PL 130.20 (statutory rape). I was not aware of this case or warrant while I was in California. Seems it was filed against me months after I left. I was arraigned on this charge and let go on ROR. Have court date in April. In New York State, what are the odds that DA office will pursue this after 16 years that charges were filed? Would they contact "complainant" to try and bring me to trial? I am not guilty of these charges and will not plea down to anything. Will go to trial, nothing less. I am really concerned and hope DA drops charges. Thank you in advance to all the counselors who can provide me with an opinion based on their past experiences.