¶33. With the benefit of these above-stated standards, we now move to the second issue: the application of the procedures in this case. The parties here agree, as do we, that it was error for the circuit court to rely upon an unsworn memo in determining whether the identities of the confidential informants should be disclosed. Section 905.10(3)(b) specifically states: “The showing [by the State] will ordinarily be in the form of affidavits but the judge may direct that testimony be taken if the judge finds that the matter cannot be resolved satisfactorily upon affidavit.” Under the plain language of the statute, affidavits or testimony are the two options given the circuit court. Both of these options provide for sworn evidence. If the judge finds that the affidavits provided are inadequate, as in this case, the court may then take testimony. By relying upon an unsworn memo, the circuit court here failed to follow the statute. Additionally, we note that the danger of relying upon unsworn evidence played out in this very case. Here, two memos purportedly from Detective Bloedorn were submitted to the court. One of those memos was a forgery created by the defendant. Fortunately, here, the forgery was discovered. We find, however, that relying upon unsworn evidence for purposes of the in camera process under Wis. Stat. § 905.10(3)(b) is error. This memo, at least as used during the in camera procedure, shall not be considered as evidence to be relied upon in this review.
¶34. We also find that the circuit court erred by independently requesting additional information from law enforcement, a request that led to receipt of the unsworn memo from Detective Bloedorn. The circuit court relied upon that independently gathered information to make a ruling on disclosure. Again, if the affidavits collected are inadequate, the judge has the option of hearing testimony. Wis. Stat. § 905.10(3)(b). Judges are generally prohibited from independently gathering evidence by the rules of judicial ethics. Supreme Court Rule 60.04(1)(g) prohibits a judge from engaging in ex parte communications concerning a pending action, with several exceptions not applicable here. The Comment to the rule states, in part, “A judge must not independently investigate facts in a case and must consider only the evidence presented.” Id. A judge must not go out and gather evidence in a pending case. To do so is error. The judge here did disclose his communication with law enforcement to both parties before ruling upon the motion for disclosure. He also provided the unsworn memo to the defense before trial. These were appropriate actions under SCR 60.04. See Comment to SCR 60.04(1)(g). These actions, though, cannot balance the potential harm done by seeking evidence independently and then relying upon such evidence in making a ruling.