Seeing as you entered a police station I would have not even considered carrying concealed or open. As others have written, fingerprint areas are used for processing both civilians conducting business or criminals. Laws may be different there but as a practice, I would not even consider carrying my weapon into a police station at all.
You were probably lucky they did not put a set of cuffs on you and question your motives.
Glad you did not make a scene, would have looked bad for the rest of the open/concealed community.
1st of all, welcome to OCDO.
Be aware you are reading the Washington forum and carrying in the public spaces of a police station is perfectly legal. Many, including myself have done so on a regular basis. Why should I be disarmed for going about my legal business, as in this case as well?
If they had put cuffs on the OP as you state and/or question his motives then the OP would have been illegally detained. What we ask here on OCDO is to follow the law. We ask that our public officials/police do the same.
What motives would they question? He was there for a legitimate and legal business transaction that is required for his business.
Again, welcome jphoenix, but please read, listen, understand before you give advice that is completely contrary to the culture of OC here in Washington.