Three years ago I was pulled over for supposed loud music violation. I submitted to a field sobriety test, which I thought I passed but the officers, eight in total still wanted a breathalyzer test. They pulled out one, then another officer said they should use the one in his trunk. I was fully cooperating but these officers were just looking for a reason too haul me in. I politely asked to do a blood draw, while not refusing anything. They were not happy about this. Fast forward a few months, I'm not a lawyer so I hired one. The lawyer was able to get all the charges dropped because the stop was unconstitutional. In the preceding three years, I have reported the incident as required by the FAA on each medical application. Yeah, I was arrested but was not convicted of anything and I don't have a DUI on my record. But that doesn't seem to matter to the FAA. A couple months ago they revisited the issue and asked for all the information pertaining to the case. I submitted that info, and a couple months later they asked why there was not a BAC test report. Well that information was never submitted to the court and my lawyer never received it either, because the case was dismissed before it was ever submitted. I called the FAA and told them the situation and asked if a written letter from my lawyer pertaining to the situation would be sufficient. The answer was yes and I did so. Last week I received another letter from the FAA saying that the letter was appreciated but insufficient and now they want my to do a HIMS evaluation. It seems as if they have gone to the full investigation mode on a charge that was fully dropped three years ago and in which I learned a valuable lesson. I have contacted Dr. Chien and he is looking into the situation, but my question is: Have any of you other aviators had to deal with the FAA after a charge has been dismissed. I'm wondering if the FAA has the legal power to pursue an investigation for a charge that doesn't legally exist anymore. Anyone that has an insight into this situation and could provide some advice, would be greatly appreciated.