906.01   General rule of competency.
906.02   Lack of personal knowledge.
906.03   Oath or affirmation.
906.04   Interpreters.
906.05   Competency of judge as witness.
906.06   Competency of juror as witness.
906.07   Who may impeach.
906.08   Evidence of character and conduct of witness.
906.09   Impeachment by evidence of conviction of crime or adjudication of delinquency.
906.10   Religious beliefs or opinions.
906.11   Mode and order of interrogation and presentation.
906.12   Writing used to refresh memory.
906.13   Prior statements of witnesses.
906.14   Calling and interrogation of witnesses by judge.
906.15   Exclusion of witnesses.
906.16   Bias of witness.
Ch. 906 Note NOTE: Extensive comments by the Judicial Council Committee and the Federal Advisory Committee are printed with chs. 901 to 911 in 59 Wis. 2d. The court did not adopt the comments but ordered them printed with the rules for information purposes.
906.01 906.01 General rule of competency. Every person is competent to be a witness except as otherwise provided in these rules.
906.01 History History: Sup. Ct. Order, 59 Wis. 2d R1, R157 (1973); Sup. Ct. Order No. 16-01, 2017 WI 13, 373 Wis. 2d xiii.
906.01 Annotation The “best evidence rule" requires production of a writing to prove its contents. There is no comparable “better evidence rule" that requires the production of an item rather than testimony about the item. York v. State, 45 Wis. 2d 550, 173 N.W.2d 693 (1970).
906.01 Annotation The trial court may not declare a witness incompetent to testify, except as provided in this section. A witness's credibility is determined by the fact finder. State v. Hanson, 149 Wis. 2d 474, 439 N.W.2d 133 (Ct. App. 1989).
906.02 906.02 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 witness. This rule is subject to the provisions of s. 907.03 relating to opinion testimony by expert witnesses.
906.02 History History: Sup. Ct. Order, 59 Wis. 2d R1, R160 (1973); 1991 a. 32.
906.02 Annotation The chain of custody to items taken from the defendant's motel room was properly established although a police department laboratory chemist who examined the same was not present to testify when uncontroverted proof showed that the condition of the exhibits had not been altered by the chemist's examination, there was no unexplained or missing link as to who had had custody, and the items were in substantially the same condition at the time of the chemist's examination as when taken from defendant's room. State v. McCarty, 47 Wis. 2d 781, 177 N.W.2d 819 (1970).
906.02 Annotation A challenge to the admissibility of boots on the ground that the victim did not properly identify them was devoid of merit, as it was stipulated that the child said they “could be" the ones the child saw. The child's lack of certitude did not preclude admissibility, but went to the weight the jury should give to the testimony. Howland v. State, 51 Wis. 2d 162, 186 N.W.2d 319 (1971).
906.03 906.03 Oath or affirmation.
906.03(1)(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 duty to do so.
906.03(2) (2)The oath may be administered substantially in the following form: Do you solemnly swear that the testimony you shall give in this matter shall be the truth, the whole truth and nothing but the truth, so help you God.
906.03(3) (3)Every person who shall declare that the person has conscientious scruples against taking the oath, or swearing in the usual form, shall make a solemn declaration or affirmation, which may be in the following form: Do you solemnly, sincerely and truly declare and affirm that the testimony you shall give in this matter shall be the truth, the whole truth and nothing but the truth; and this you do under the pains and penalties of perjury.
906.03(4) (4)The assent to the oath or affirmation by the person making it may be manifested by the uplifted hand.
906.03 History History: Sup. Ct. Order, 59 Wis. 2d R1, R161 (1973); 1991 a. 32.
906.03 Annotation A witness who is a young child need not be formally sworn to meet the oath or affirmation requirement. State v. Hanson, 149 Wis. 2d 474, 439 N.W.2d 133 (1989).
906.03 Annotation The purpose of an oath or affirmation is to impress upon the swearing individual an appropriate sense of obligation to tell the truth. The statutes do not invoke specific, mandated language or formulaic procedures in the administration of an oath or affirmation. The oath or affirmation requirement is an issue of substance, not form. State v. Moeser, 2022 WI 76, 405 Wis. 2d 1, 982 N.W.2d 45, 19-2184.
906.04 906.04 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.
906.04 History History: Sup. Ct. Order, 59 Wis. 2d R1, R162 (1973); 1981 c. 390; 1991 a. 32.
906.05 906.05 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.
906.05 History History: Sup. Ct. Order, 59 Wis. 2d R1, R163 (1973).
906.05 Annotation A judge who carefully considered the transcribed record and the judge's recollection of a previous proceeding involving the defendant did not impermissibly testify. State v. Meeks, 2002 WI App 65, 251 Wis. 2d 361, 643 N.W.2d 526, 01-0263.
906.05 AnnotationReversed on other grounds. 2003 WI 104, 263 Wis. 2d 794, 666 N.W.2d 859, 01-0263.
906.06 906.06 Competency of juror as witness.
906.06(1)(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 opportunity to object out of the presence of the jury.
906.06(2) (2) Inquiry into validity of verdict or indictment. Upon an inquiry into the validity of a verdict or indictment, a juror may not testify as to any matter or statement occurring during the course of the jury's deliberations or to the effect of anything upon the juror's or any other juror's mind or emotions as influencing the juror to assent to or dissent from the verdict or indictment or concerning the juror's mental processes in connection therewith, except that a juror may testify on the question whether extraneous prejudicial information was improperly brought to the jury's attention or whether any outside influence was improperly brought to bear upon any juror. Nor may the juror's affidavit or evidence of any statement by the juror concerning a matter about which the juror would be precluded from testifying be received.
906.06 History History: Sup. Ct. Order, 59 Wis. 2d R1, R165 (1973); 1991 a. 32.
906.06 Annotation Verdict impeachment requires evidence that is: 1) competent; 2) shows substantive grounds sufficient to overturn the verdict; and 3) shows resulting prejudice. Discussing impeachment of a verdict through juror affidavits or testimony. After Hour Welding, Inc. v. Laneil Management Co., 108 Wis. 2d 734, 324 N.W.2d 686 (1982).
906.06 Annotation There was probable prejudice when the question of a depraved mind was central and a juror went to the jury room with a dictionary definition of “depraved" written on a card. State v. Ott, 111 Wis. 2d 691, 331 N.W.2d 629 (Ct. App. 1983).
906.06 Annotation A conviction was reversed when extraneous information improperly brought to the jury's attention raised a reasonable possibility that the information had a prejudicial effect on the hypothetical average jury. State v. Poh, 116 Wis. 2d 510, 343 N.W.2d 108 (1984).
906.06 Annotation Evidence of a juror's racially-prejudiced remark during jury deliberations was not competent under sub. (2). State v. Shillcutt, 119 Wis. 2d 788, 350 N.W.2d 686 (1984).
906.06 Annotation In any jury trial, material prejudice on the part of any juror impairs the right to a jury trial. That prejudicial material was brought to only one juror's attention and was not communicated to any other jurors is irrelevant to determining whether that information was “improperly brought to the jury's attention" under sub. (2). Castenada v. Pederson, 185 Wis. 2d 200, 518 N.W.2d 246 (1994), State v. Messelt, 185 Wis. 2d 255, 518 N.W.2d 232 (1994).
906.06 Annotation Extraneous information is information, other than the general wisdom that a juror is expected to possess, that a juror obtains from a non-evidentiary source. A juror who consciously brings non-evidentiary objects to show the other jurors improperly brings extraneous information before the jury. State v. Eison, 188 Wis. 2d 298, 525 N.W.2d 91 (Ct. App. 1994).
906.06 Annotation Sub. (2) does not limit the testimony of a juror regarding clerical errors in a verdict. A written verdict not reflecting the jury's oral decision may be impeached by showing in a timely manner and beyond a reasonable doubt that all jurors are in agreement that an error was made. State v. Williquette, 190 Wis. 2d 678, 526 N.W.2d 144 (Ct. App. 1995).
906.06 Annotation Outlining an analytical framework to be used to determine whether a new trial on the grounds of prejudice due to extraneous juror information. State v. Eison, 194 Wis. 2d 160, 533 N.W.2d 738 (1995).
906.06 Annotation Jurors may rely on their common sense and life experience during deliberations, including expertise that a juror may have on a particular subject. That a juror was a pharmacist did not make the juror's knowledge about the particular effect of a drug extraneous information subject to inquiry under sub. (2). State v. Heitkemper, 196 Wis. 2d 218, 538 N.W.2d 561 (Ct. App. 1995), 94-2659.
906.06 Annotation The extraneous information exception under sub. (2) is not limited to factual information but also includes legal information obtained outside the proceeding. State v. Wulff, 200 Wis. 2d 318, 546 N.W.2d 522 (Ct. App. 1996), 95-1732.
906.06 Annotation Generally, the sole area jurors are competent to testify to is whether extraneous information was considered. Except when juror bias goes to a fundamental issue such as religion, evidence of juror perceptions is not competent, no matter how mistaken, and cannot form the basis for granting a new trial. Anderson v. Burnett County, 207 Wis. 2d 587, 558 N.W.2d 636 (Ct. App. 1996), 96-0954.
906.06 Annotation The trial court, and not the defendant or the defendant's attorney, is permitted to question a juror directly at a hearing regarding juror bias. The trial court's discretion in submitting questions suggested by the defendant is limited, but the failure to submit questions is subject to harmless error evaluation. State v. Delgado, 215 Wis. 2d 16, 572 N.W.2d 479 (Ct. App. 1997), 96-2194.
906.06 Annotation It was reasonable to refuse to allow a former member of the jury from testifying as a witness in the same case. Broadhead v. State Farm Mutual Automobile Insurance Co., 217 Wis. 2d 231, 579 N.W.2d 761 (Ct. App. 1998), 97-0904.
2021-22 Wisconsin Statutes updated through 2023 Wis. Act 240 and through all Supreme Court and Controlled Substances Board Orders filed before and in effect on May 30, 2024. Published and certified under s. 35.18. Changes effective after May 30, 2024, are designated by NOTES. (Published 5-30-24)