Expungement

It sounds as if your official court records were erased/expunged, but the arrest record was not.  This is not unusual.  The police and the courts keep different records.  Moreover, there are different burdens of proof for the police (probable cause) and the prosecutor (proof beyond a reasonable doubt).  In any event, once your charges are dismissed and expunged from the court system, the police will usually either return or destory your arrest record (fingerprints, mugshot, etc.), upon request and upon providing them with proof of the dismissal/expungement.  I suggest calling your attorney and discussing it with him.  He may offer to write a letter to the jail/police, or he may instruct you on a simple way to do it yourself.  Good luck.