Wis. Stat. § 968.53
Members of the grand jury and any grand jury reporter may be required by any court to testify whether the testimony of a witness examined before the jury is consistent with or different from the evidence given by the witness before the court; and they may also be required to disclose the testimony given before the grand jury by any person upon a complaint against the person for perjury, or upon trial for the offense. Any transcript of testimony taken before the grand jury and certified by a grand jury reporter to have been carefully compared by the reporter with his or her minutes of testimony so taken and to be a true and correct transcript of all or a specified portion of the transcript, may be received in evidence with the same effect as the oral testimony of the reporter to the facts so certified, but the reporter may be cross-examined by any party as to the matter.
Wis. Stat. § 968.53