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 person with respect to whom the request has been filed. All persons not necessary for the conduct of the proceedings may be excluded. The court shall receive all relevant and material evidence which may be offered. The rules governing evidentiary and procedural matters shall be applied to hearings under this section in a manner so as to facilitate informal, efficient presentation of all relevant, probative evidence and resolution of issues with due regard to the interests of all parties. The facts or data upon which a duly qualified expert bases an opinion or inference may be those perceived by or made known to the expert at or before the hearing and if of a type reasonably relied upon by experts in their particular field in forming opinions or inferences upon the subject, the facts or data need not be admissible in evidence. The expert may testify in terms of opinion or inference and give the expert's reasons therefor without prior disclosure of the underlying facts or data unless the court requires otherwise. If requested on cross-examination, the expert shall disclose the underlying facts or data.
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 person with respect to whom the request has been filed is a person with an alcohol or substance abuse problem subject to involuntary commitment for care and treatment under this act, and that it would be in the best interests of the person to be detained until the trial upon the petition.
K.S.A. 59-29b59