may ask a court for permission to consider a witness hostile only under certain circumstances. First and foremost, the witness must be under direct examination
, and not cross examination
. This is because during cross examination, the witness is already considered to be hostile.
The reason a lawyer must have a witness considered hostile during direct examination is because (s)he is not allowed to ask leading questions of their own witness unless they are determined to be hostile. Once a witness has been declared hostile, another word for uncooperative, the lawyer may ask the leading questions he needs to, to get the answers out of the witness.