Sorry to be unhelpful, but frankly, he's going to have to discuss this with an attorney, for sure. There's just no shortcut or easy answer to this question. The issue is not so much whether he can 'still' be charged-- it may well be that he was charged all those years ago, and that at least technically stops the clock running on a statute of limitations. That's NOT to say that they'll still be able to prosecute your husband, but it would still certainly muck up the immigration process. Which means he's going to need a criminal attorney without any doubt. If a criminal process was started (and if a warrant issued, it probably was, though that's not a certainty) it's going to take an attorney to clear it up in an expeditious fashion.
Any answer provided on Avvo, including this one, is a general answer about a legal question, not specific legal advice. Different lawyers may analyze this or any other matter differently, especially if there are additional facts not reflected in the question. I am not your attorney until retained by a written retainer agreement signed by both of us. I licensed in the state of California and the Central District of the Ninth Circuit.
I recommend going to the Clerk of the Courthouse where he was going to appear and print out the docket, which is the list of all dates and what happened, and then take it to a local criminal attorney to see what the options are - there may be more than one issue lurking in this case history. The docket will greatly assist any attorney and remove guesswork and lead to more helpful answers. good luck.
Behar Intl. Counsel 619.234.5962 Kindly be advised that the answer above is only general in nature cannot be construed as legal advice, given that not enough facts are known. It is your responsibility to retain a lawyer to analyze the facts specific to your particular situation in order to give you specific advice. Specific answers will require cognizance of all pertinent facts about your case. Any answers offered on Avvo are of a general nature only, and are not meant to create an attorney-client relationship.