Which is correct:
I have been asked by attorney Smith to inspect the documents.
or
I have been asked by Attorney Smith to inspect the documents.
Which is correct:
I have been asked by attorney Smith to inspect the documents.
or
I have been asked by Attorney Smith to inspect the documents.
Neither! In the US, if Mr. Smith is the US federal or a state Attorney General then you may use Attorney General Smith. If you have been asked by a lawyer to inspect documents (presumably in an lawyer-client situation) then you should write, "I have been asked by my/his/their attorney to inspect the documents".