Pen. Code, § 1119

When, in the opinion of the court, it is proper that the jury should view the place in which the offense is charged to have been committed, or in which any other material fact occurred, or any personal property which has been referred to in the evidence and cannot conveniently be brought into the courtroom, it may order the jury to be conducted in a body, in the custody of the sheriff or marshal, as the case may be, to the place, or to the property, which must be shown to them by a person appointed by the court for that purpose; and the officer must be sworn to suffer no person to speak or communicate with the jury, nor to do so himself or herself, on any subject connected with the trial, and to return them into court without unnecessary delay, or at a specified time.