Pen. Code, § 1355

When the commission is ordered, the defendant must serve upon the District Attorney, without delay, a copy of the interrogatories to be annexed thereto, with two days’ notice of the time at which they will be presented to the Court or Judge. The District Attorney may in like manner serve upon the defendant or his counsel cross-interrogatories, to be annexed to the commission, with the like notice. In the interrogatories either party may insert any questions pertinent to the issue. When the interrogatories and cross-interrogatories are presented to the Court or Judge, according to the notice given, the Court or Judge must modify the questions so as to conform them to the rules of evidence, and must indorse upon them his allowance and annex them to the commission.