Not the right board, but never mind. I don't know of any law that says an institution -- employer or otherwise -- isn't free to ask about arrests/convictions.
If you've had X expunged, then by law you're free to say "no" as to that arrest/conviction ... because as a legal matter they didn't happen once the expungement is granted. Of course, certain agencies will still have and have access to this info, but unless you're looking for a government job that requires a clearance and such ...

