Chapter XII Expert Evidence

The court may order expert examination from a person with relevant knowledge and experience.

The court must have expert witnesses swear an oath.

①When it is necessary to have an expert witness examine the mental or physical condition of the defendant, the court may detain the defendant at a hospital or any other appropriate place, and determine a time period for the detaining.

②The detention in the preceding paragraph must not be executed without a detention warrant for expert examination.

③When it is necessary for the detention prescribed in paragraph (1) of this Article, the court may, upon a proposal from the custodian of the hospital or other place accommodating the defendant or ex officio, order a judicial police official to guard the defendant.

④The court may, when it is necessary, extend or shorten a period of detention.

⑤The provisions pertaining to detention apply mutatis mutandis to the detention for expert examination prescribed in paragraph (1) of this Article except as otherwise provided in this Code; provided however, that the provisions pertaining to bail do not apply.

⑥The detention prescribed in paragraph (1) of this Article is deemed as detention with regard to the inclusion of the number of pre-sentencing detention days.

①When a detention warrant for expert examination is executed against a defendant under detention, the execution of detention is deemed to be suspended while said defendant is under detention for expert examination.

②In the case of the preceding paragraph, when the disposition prescribed in paragraph (1) of the preceding Article has been rescinded or the period of detention has expired, the provisions of Article 98 apply mutatis mutandis.

①Expert witnesses may, upon the permission of the court and when it is necessary for expert examination, enter a person's residence, or premises, building or vessel guarded by a person, or conduct inspections and examinations of persons, perform autopsies, excavate graves or break objects.

②The court must, when it gives permission as prescribed in the preceding paragraph, issue a written permit which contains the name of the defendant, the crime, and the place to be entered, the body to be inspected and examined, the corpse to be autopsied, the grave to be excavated, the object to be destroyed and the name of the expert witness and other particulars provided for by the Rules of Court.

③The court may add appropriate conditions to inspections and examinations of persons.

④Expert witnesses must show a written permit to the relevant persons subject to the measures prescribed in paragraph (1) of this Article.

⑤The provisions of the preceding three paragraphs do not apply to the measures prescribed in paragraph (1) of this Article taken by an expert witness in a public court.

⑥The provisions of Articles 131, 137, 138 and 140 apply mutatis mutandis to inspections and examinations of persons by an expert witness in accordance with the provisions of paragraph (1) of this Article.

The court may have a judge of a panel take necessary dispositions for expert examination; provided however, that this does not apply to the disposition provided for in Article 167, paragraph (1).

A public prosecutor or defense counsel may attend expert examination. In this case, the provisions of Article 157, paragraph (2) apply mutatis mutandis.

The provisions of the preceding Chapter apply mutatis mutandis to expert examination, except for the provisions on subpoena. In this case, the phrase "when a court finds it appropriate in the following cases," in Article 157-6, paragraph (2) is deemed to be replaced with "when a court finds it appropriate in the following cases, or when examining an expert witness (excluding examination concerning the process and conclusion of the expert examination) and the court finds it appropriate,".

①When a person who is to undergo an inspection and examination of a person refuses to be inspected and examined by an expert witness prescribed in Article 168, paragraph (1), said expert witness may request a judge to conduct said inspection and examination of the person.

②The judge who is requested as prescribed in the preceding paragraph may inspect and examine a person in accordance with the provisions of Chapter X.

①Expert witnesses may request expert examination fees in addition to travel expenses, a daily allowance and accommodation fees, and receive payment or reimbursement of the expenses necessary for said expert examination.

②If an expert witness receives the payment of expenses necessary for expert examination in advance but does not appear in court or refuses to swear an oath or perform said examination without a justifiable reason, said expert witness must return said received expenses.

With regard to examinations pertaining to past facts which have come to be known through special knowledge, the provisions of the preceding Chapter apply instead of the provisions of this Chapter.