Someone who questions a witness carefully (especially about testimony given earlier)(noun)
WordNet. Princeton University. 2010.
Use "cross-questioner" in a sentence
"“Do,” said I, very glad to dismiss the topic, and especially glad to have baffled the sagacity of my cross-questioner — if, indeed, I had baffled it; for though his words now led away from the dangerous point, his eyes, keen and watchful, seemed still preoccupied with the former idea."
"But old Tinker was not to be pumped by this little cross-questioner; and signifying to her that bed was a place for sleeping, not conversation, set up in her corner of the bed such a snore as only the nose of innocence can produce."
"They fear the intentions of the cross-questioner, and they hold themselves safest behind a crooked answer."