Whenever a proposed patient who is not subject to a temporary custody order issued pursuant to Kan. Stat. Ann. §§ 59-2959 and amendments thereto requests a hearing pursuant to this section, a hearing shall be held within a reasonable time thereafter. The petitioner and the proposed patient shall be notified of the time and place of the hearing, afforded an opportunity to testify, and to present and cross-examine witnesses. The proposed patient shall be present at the hearing, and the proposed patient’s presence cannot be waived. All persons not necessary for the conduct of the proceedings may be excluded. The hearing shall be conducted in as informal a manner as may be consistent with orderly procedure and in a physical setting not likely to have a harmful effect on the welfare of the proposed patient. The court shall receive all relevant and material evidence which may be offered. If the petitioner is not represented by counsel, the county or district attorney shall represent the petitioner, prepare all necessary papers, appear at the hearing and present such evidence as the county or district attorney determines to be of aid to the court in determining whether or not there is probable cause to believe that the proposed patient is a mentally ill person subject to involuntary commitment for care and treatment under this act. If the court determines from the evidence that there is probable cause to believe that the proposed patient is a mentally ill person subject to involuntary commitment, the court shall issue the order for a mental evaluation; otherwise, the court shall terminate the proceedings.