Wis. Stat. § 971.23 — WI Code / Chapter 971 / Section 971.23
Discovery and inspection.
Status: in_force

(1) What a district attorney must disclose to a defendant. Upon demand, the district attorney shall, within a reasonable time before trial, disclose to the defendant or his or her attorney and permit the defendant or his or her attorney to inspect and copy or photograph all of the following materials and information, if it is within the possession, custody or control of the state:

(a) Any written or recorded statement concerning the alleged crime made by the defendant, including the testimony of the defendant in a secret proceeding under s. 968.26 or before a grand jury, and the names of witnesses to the defendant’s written statements.

(b) A written summary of all oral statements of the defendant which the district attorney plans to use in the course of the trial and the names of witnesses to the defendant’s oral statements.

(bm) Evidence obtained in the manner described under s. 968.31 (2) (b) , if the district attorney intends to use the evidence at trial.

(c) A copy of the defendant’s criminal record.

(d) A list of all witnesses and their addresses whom the district attorney intends to call at the trial. This paragraph does not apply to rebuttal witnesses or those called for impeachment only.

(e) Any relevant written or recorded statements of a witness named on a list under par. (d) , including any audiovisual recording of an oral statement of a child under s. 908.08 , any reports or statements of experts made in connection with the case or, if an expert does not prepare a report or statement, a written summary of the expert’s findings or the subject matter of his or her testimony, and the results of any physical or mental examination, scientific test, experiment or comparison that the district attorney intends to offer in evidence at trial.

(f) The criminal record of a prosecution witness which is known to the district attorney.

(g) Any physical evidence that the district attorney intends to offer in evidence at the trial.

(h) Any exculpatory evidence.

(2m) What a defendant must disclose to the district attorney. Upon demand, the defendant or his or her attorney shall, within a reasonable time before trial, disclose to the district attorney and permit the district attorney to inspect and copy or photograph all of the following materials and information, if it is within the possession, custody or control of the defendant:

(a) A list of all witnesses, other than the defendant, whom the defendant intends to call at trial, together with their addresses. This paragraph does not apply to rebuttal witnesses or those called for impeachment only.

(am) Any relevant written or recorded statements of a witness named on a list under par. (a) , including any reports or statements of experts made in connection with the case or, if an expert does not prepare a report or statement, a written summary of the expert’s findings or the subject matter of his or her testimony, and including the results of any physical or mental examination, scientific test, experiment or comparison that the defendant intends to offer in evidence at trial.

(b) The criminal record of a defense witness, other than the defendant, which is known to the defense attorney.

(c) Any physical evidence that the defendant intends to offer in evidence at the trial.

(3) Comment or instruction on failure to call witness. No comment or instruction regarding the failure to call a witness at the trial shall be made or given if the sole basis for such comment or instruction is the fact the name of the witness appears upon a list furnished pursuant to this section.

(5) Scientific testing. On motion of a party subject to s. 971.31 (5) , the court may order the production of any item of physical evidence which is intended to be introduced at the trial for scientific analysis under such terms and conditions as the court prescribes.

(5c) Psychiatric testing of victims or witnesses. In a prosecution of s. 940.225 , 948.02 , or 948.025 or of any other crime if the court determines that the underlying conduct was sexually motivated, as defined in s. 980.01 (5) , the court may not order any witness or victim, as a condition of allowing testimony, to submit to a psychiatric or psychological examination to assess his or her credibility.

(6) Protective order. Upon motion of a party, the court may at any time order that discovery, inspection or the listing of witnesses required under this section be denied, restricted or deferred, or make other appropriate orders. If the district attorney or defense counsel certifies that to list a witness may subject the witness or others to physical or economic harm or coercion, the court may order that the deposition of the witness be taken pursuant to s. 967.04 (2) to (6) . The name of the witness need not be divulged prior to the taking of such deposition. If the witness becomes unavailable or changes his or her testimony, the deposition shall be admissible at trial as substantive evidence.

(6c) Interviews of victims by defense. Except as provided in s. 967.04 , the defendant or his or her attorney may not compel a victim of a crime to submit to a pretrial interview or deposition.

(6m) In camera proceedings. Either party may move for an in camera inspection by the court of any document required to be disclosed under sub. (1) or (2m) for the purpose of masking or deleting any material which is not relevant to the case being tried. The court shall mask or delete any irrelevant material.

(7) Continuing duty to disclose. If, subsequent to compliance with a requirement of this section, and prior to or during trial, a party discovers additional material or the names of additional witnesses requested which are subject to discovery, inspection or production under this section, the party shall promptly notify the other party of the existence of the additional material or names.

(7m) Sanctions for failure to comply.

(a) The court shall exclude any witness not listed or evidence not presented for inspection or copying required by this section, unless good cause is shown for failure to comply. The court may in appropriate cases grant the opposing party a recess or a continuance.

(b) In addition to or in lieu of any sanction specified in par. (a) , a court may, subject to sub. (3) , advise the jury of any failure or refusal to disclose material or information required to be disclosed under sub. (1) or (2m) , or of any untimely disclosure of material or information required to be disclosed under sub. (1) or (2m) .

(8) Notice of alibi.

(a) If the defendant intends to rely upon an alibi as a defense, the defendant shall give notice to the district attorney at the arraignment or at least 30 days before trial stating particularly the place where the defendant claims to have been when the crime is alleged to have been committed together with the names and addresses of witnesses to the alibi, if known. If at the close of the state’s case the defendant withdraws the alibi or if at the close of the defendant’s case the defendant does not call some or any of the alibi witnesses, the state shall not comment on the defendant’s withdrawal or on the failure to call some or any of the alibi witnesses. The state shall not call any alibi witnesses not called by the defendant for the purpose of impeaching the defendant’s credibility with regard to the alibi notice. Nothing in this section may prohibit the state from calling said alibi witnesses for any other purpose.

(b) In default of such notice, no evidence of the alibi shall be received unless the court, for cause, orders otherwise.

(c) The court may enlarge the time for filing a notice of alibi as provided in par. (a) for cause.

(d) Within 20 days after receipt of the notice of alibi, or such other time as the court orders, the district attorney shall furnish the defendant notice in writing of the names and addresses, if known, of any witnesses whom the state proposes to offer in rebuttal to discredit the defendant’s alibi. In default of such notice, no rebuttal evidence on the alibi issue shall be received unless the court, for cause, orders otherwise.

(e) A witness list required under par. (a) or (d) shall be provided in addition to a witness list required under sub. (1) (d) or (2m) (a) , and a witness disclosed on a list under sub. (1) (d) or (2m) (a) shall be included on a list under par. (a) or (d) if the witness is required to be disclosed under par. (a) or (d) .

(9) Deoxyribonucleic acid evidence.

(a) In this subsection “deoxyribonucleic acid profile” has the meaning given in s. 939.74 (2d) (a) .

(b) Notwithstanding sub. (1) (e) or (2m) (am) , if either party intends to submit deoxyribonucleic acid profile evidence at a trial to prove or disprove the identity of a person, the party seeking to introduce the evidence shall notify the other party of the intent to introduce the evidence in writing by mail at least 45 days before the date set for trial; and shall provide the other party, within 15 days of request, the material identified under sub. (1) (e) or (2m) (am) , whichever is appropriate, that relates to the evidence.

(c) The court shall exclude deoxyribonucleic acid profile evidence at trial, if the notice and production deadlines under par. (b) are not met, except the court may waive the 45 day notice requirement or may extend the 15 day production requirement upon stipulation of the parties, or for good cause, if the court finds that no party will be prejudiced by the waiver or extension. The court may in appropriate cases grant the opposing party a recess or continuance.

(10) Payment of copying costs in cases involving indigent defendants. When the state public defender or a private attorney appointed under s. 977.08 requests copies, in any format, of any item that is discoverable under this section, the state public defender shall pay any fee charged for the copies from the appropriation account under s. 20.550 (1) (a) . If the person providing copies under this section charges the state public defender a fee for the copies, the fee may not exceed the applicable maximum fee for copies of discoverable materials that is established by rule under s. 977.02 (9) .

(11) Child pornography recordings.

(a) In this subsection:

1. “Defense” means the defendant, his or her attorney, and any individual retained by the defendant or his or her attorney for the purpose of providing testimony if the testimony is expert testimony that relates to an item or material included under par. (b) .

2. “Reasonably available” means sufficient opportunity for inspection, viewing, and examination at a law enforcement or government facility.

3. “Sexually explicit conduct” has the meaning given in s. 948.01 (7) .

(b) Any undeveloped film, photographic negative, photograph, motion picture, videotape, or recording, which includes any item or material that would be included under s. 948.01 (3r) , or any copy of the foregoing, that is of a person who has not attained the age of 18 and who is engaged in sexually explicit conduct and that is in the possession, custody, and control of the state shall remain in the possession, custody, and control of a law enforcement agency or a court but shall be made reasonably available to the defense.

(c)

1. Notwithstanding sub. (1) (e) and (g) , a court shall deny any request by the defense to provide, and a district attorney or law enforcement agency may not provide to the defense, any item or material required in par. (b) to remain in the possession, custody, and control of a law enforcement agency or court, except that a court may order that a copy of an item or material included under par. (b) be provided to the defense if that court finds that a copy of the item or material has not been made reasonably available to the defense. The defense shall have the burden to establish that the item or material has not been made reasonably available.

2. If a court orders under subd. 1. a copy of an item or material included under par. (b) to be provided to the defense, the court shall enter a protective order under sub. (6) that includes an order that the copy provided to the defense may not be copied, printed, or disseminated by the defense and shall be returned to the court or law enforcement agency, whichever is appropriate, at the completion of the trial.

(d) Any item or material that is required under par. (b) to remain in possession, custody, and control of a law enforcement agency or court is not subject to the right of inspection or copying under s. 19.35 (1) .

(12) Definitions. In this section:

(a)

1. Subject to subds. 2. and 3. , “address” means an individual’s residential street address.

2. If the individual under subd. 1. is a witness who is a law enforcement officer, tribal law enforcement officer, public officer, or public employee whose testimony will be regarding events or actions taken in the individual’s official capacity or within the scope of the individual’s employment, “address” means the street address of the primary location of the employer where the individual is or was employed at the time of the events or actions that are subject to discovery under this section.

3. If the individual under subd. 1. is a witness who is a participant in the address confidentiality program under s. 165.68 , “address” means the assigned address designated for the individual by the department of justice.

(b) “Law enforcement officer” has the meaning given in s. 165.85 (2) (c) .

(c) “Public officer” and “public employee” have the meaning given in s. 939.22 (30) .

(d) “Tribal law enforcement officer” has the meaning given in s. 165.85 (2) (g) .

History: 1973 c. 196 ; 1975 c. 378 , 421 ; 1989 a. 121 ; 1991 a. 223 ; 1993 a. 16 , 486 ; 1995 a. 27 , 387 ; 2001 a. 16 ; 2005 a. 42 , 279 ; 2007 a. 20 ; 2009 a. 28 , 138 , 276 ; 2011 a. 284 ; 2017 a. 59 ; 2025 a. 150 .