Chapter 906 — EVIDENCE — WITNESSES

906.01 General rule of competency. Every person is competent to be a witness except as otherwise provided in these rules. History: Sup. Ct. Order, 59 Wis. 2d R1, R157 (1973); Sup. Ct. Order No. 16-01, 2017 WI 13, 373 Wis. 2d xiii. The “best evidence rule” requires production of a…

906.02 Lack of personal knowledge. A witness may not testify to a matter unless evidence is introduced sufficient to support a finding that the witness has personal knowledge of the matter. Evidence to prove personal knowledge may, but need not, consist of the testimony of the wi…

906.03 Oath or affirmation. (1) Before testifying, every witness shall be required to declare that the witness will testify truthfully, by oath or affirmation administered in a form calculated to awaken the witness’s conscience and impress the witness’s mind with the witness’s du…

906.04 Interpreters. An interpreter is subject to the provisions of chs. 901 to 911 relating to qualification as an expert and the administration of an oath or affirmation that the interpreter will make a true translation. History: Sup. Ct. Order, 59 Wis. 2d R1, R162 (1973); 1981…

906.05 Competency of judge as witness. The judge presiding at the trial may not testify in that trial as a witness. No objection need be made in order to preserve the point. History: Sup. Ct. Order, 59 Wis. 2d R1, R163 (1973). A judge who carefully considered the transcribed reco…

906.06 Competency of juror as witness. (1) AT THE TRIAL. A member of the jury may not testify as a witness before that jury in the trial of the case in which the member is sitting as a juror. If the juror is called so to testify, the opposing party shall be afforded an opportunit…

906.07 Who may impeach. The credibility of a witness may be attacked by any party, including the party calling the witness. History: Sup. Ct. Order, 59 Wis. 2d R1, R169 (1973); 1991 a. 32. 906.08 Evidence of character and conduct of witness. Updated 23-24 Wis. Stats. 2 (1) OPINIO…

906.09 Impeachment by evidence of conviction of crime or adjudication of delinquency. (1) GENERAL RULE. For the purpose of attacking character for truthfulness, a witness may be asked whether the witness has ever been convicted of a crime or adjudicated delinquent and the number …

906.10 Religious beliefs or opinions. Evidence of the beliefs or opinions of a witness on matters of religion is not admissible for the purpose of showing that by reason of their nature the witness’s credibility is impaired or enhanced. History: Sup. Ct. Order, 59 Wis. 2d R1, R18…

906.11 Mode and order of interrogation and presentation. (1) CONTROL BY JUDGE. The judge shall exercise reasonable control over the mode and order of interrogating witnesses and presenting evidence so as to do all of the following: (a) Make the interrogation and presentation effe…

906.12 Writing used to refresh memory. If a witness uses a writing to refresh the witness’s memory for the purpose of testifying, either before or while testifying, an adverse party is entitled to have it produced at the hearing, to inspect it, to cross-examine the witness thereo…

906.13 Prior statements of witnesses. (1) EXAMINING WITNESS CONCERNING PRIOR STATEMENT. In examining a witness concerning a prior statement made by the witness, whether written or not, the statement need not be shown or its contents disclosed to the witness at that time, but on r…

906.14 Calling and interrogation of witnesses by judge. (1) CALLING BY JUDGE. The judge may, on the judge’s own motion or at the suggestion of a party, call witnesses, and all parties are entitled to cross-examine witnesses thus called. (2) INTERROGATION BY JUDGE. The judge may i…

906.15 Exclusion of witnesses. (1) At the request of a party, the judge or a circuit court commissioner shall order witnesses excluded so that they cannot hear the testimony of other witnesses. The judge or circuit court commissioner may also make the order of his or her own moti…

906.16 Bias of witness. For the purpose of attacking the credibility of a witness, evidence of bias, prejudice, or interest of the witness for or against any party to the case is admissible. May 22, 2026, are designated by NOTES. (Published 5-22-26)