The presiding justice of the superior court and the chief judge of the family court may assign a justice of those courts or the jury commissioner for the purpose of qualifying petit jurors and dividing the petit jury panels into subpanels. The assigned justice shall order the panel of petit jurors to be divided into two (2) or more subpanels, constituting of not less than twenty-five (25) members each in criminal cases and fifteen (15) members each in civil cases, so that juries may be impaneled from less than the total number summoned in several courtrooms and in civil and criminal cases at the same time; and the assigned justice may thereafter order the consolidation of several subpanels or all of them or may order additions to each of them from other subpanels and may continue, in like manner, as often as he or she shall deem it to be necessary to accomplish the purpose of this section. The subdivision of the panel into subpanels and additions to the subpanels shall be by lot and the names of jurors so drawn by lot shall be placed in a box provided for that purpose.