Just an update to my post above. When we arrived at the interview the agent asked if I had ever been arrested. I said yes and related the circumstances. He was very nice about it, stating I needed proof from Nevada that no charges were filed, and even indicated that he would be all set to approve me as soon as he had that proof. He gave me the FBI case number and an instruction sheet.
So I had to call the District Attorney office in the town where it happened. They asked me to fax them the details, which I did, and then I sat nervously for two weeks wondering if the fax went into a black hole. Finally I called to follow up and the woman who answered the phone immediately knew what I was referring to and told me they were searching in their offsite archives and could find nothing. Eventually, an e-mail with an attached letter arrived signed by the DA stating that they had reviewed all available records and could find no indication that charges had been filed.
I e-mailed the attachment directly to the CPB Officer, and within an hour, received an e-mail from GOES stating that there had been a change to my status. So I logged in and lo and behold, indeed approved!
So all is not list if you have an arrest record.
I guess I am curious in our data driven age, why law enforcement would maintain records of an arrest, but have no documentation whatsoever that the charges had been dropped/dismissed. I know this was back in 1987, but it seems that there should be some mechanism to permanently note the final disposition of an arrest. Instead, they apparently had to spend considerable time searching their archives just to come up with a letter that stated they could find no record of charges being filed.