When all the parties named in the petition have been summoned or notified, in the manner provided, and the time for their appearance shall have expired, the court shall hear any and all persons who shall have appeared and interposed objections to the petition or proceedings, and proceed to decide the questions raised, and may vacate the petition, or any part of the proceedings for cause, and may allow amendments of the petition, in form or substance, as the right of the matter shall demand. If any person having an interest in the land has been overlooked, or not summoned or notified, the court may continue the proceedings and cause such person to be served or notified. If the petition and proceedings are sustained, the court shall appoint 3 commissioners, residents and freeholders within the county, not interested or of kin to any of the persons interested in the land to ascertain and determine the necessity of the proposed public use, the necessity for using such property and the just compensation to be paid therefor by the state, which ought to be paid by the state to each of the owners and persons interested in the premises, as and for his, her or their just compensation for the land sought to be taken. Such commissioners before entering upon their duties as such shall take an oath in substantially the following form: "We do each of us solemnly swear that we will faithfully and justly determine the public necessity of the proposed use, the necessity of taking the property described in the petition filed in this cause and the amount of compensation which ought to be paid to each of the owners and persons interested in the premises described in said petition according to our best ability." They shall visit the land sought to be acquired, shall ascertain the separate interest of each person owning or interested in any part of the premises, and the description of his or her separate interest in the parcel; shall hear, in the presence and under direction of the court, evidence touching the matters they are to find, brought forward by any person having an interest, and shall find all necessary facts to possess the court with the truth and right of the matter, but shall not be required to find what evidence was offered or given, and shall report to the court, in writing, their findings. Instead of commissioners, the court, with or without the request of any person interested in any portion of the premises described in the petition, may, and upon the request of any such person shall, order a venire to issue to the sheriff, to summon 12 jurors who shall be residents and freeholders of the county where the land is situated, to attend at a time to be named, before the court, to serve as a jury. Any person interested in any part of the premises may object for cause to any of the jurors, but there shall be no peremptory challenge allowed. In case any juror fails to appear, is excused, or set aside from the panel, the court may order the sheriff, or other proper officer in attendance, to summon forthwith the requisite number of talesmen to form the jury. The jury shall be sworn, as is required of commissioners, and they shall view the premises, hear evidence if offered, determine the necessity of the public use, the necessity for taking such property and the amount of compensation to be paid therefor and the same proceedings be had as near as may be, as hereinbefore required in reference to commissioners.