¶35. We think it will be a rare case that the State is able to meet its burden of proof at a Miranda–Goodchild hearing by relying exclusively on an unsworn police report.
¶36. In this case, the State did not meet its burden of proof.
The court explicitly says that this is a “fact-specific matter,” ¶5, which might seem to limit its effect. The long and short of it is that the DA wasn’t ready to go forward with a suppression hearing, but the trial judge found on the basis of police reports that the state had nonetheless met its burden, which then shifted to Jiles. The rules of evidence don’t apply to suppression hearings, ¶29, citing § 901.04(1); it follows that live testimony from police officers is not always required, ¶31. Nonetheless, the court cautions, in the paragraphs quoted above, that exclusive reliance on unsworn documents, will rarely suffice – and that’s about as close to a general rule as you’ll find in this case. However, the court’s comments about the involvement of the trial judge will also be of generalized interest:
¶39. The Miranda–Goodchild hearing is an evidentiary hearing for the parties. It is not a soliloquy for the court. The court must not permit itself to become a witness or an advocate for one party. A defendant does not receive a full and fair evidentiary hearing when the role of the prosecutor is played by the judge and the assistant district attorney is reduced to a bystander. We hold that the procedure employed by the court in this hearing did not conform with the minimum requirements of § 971.31(3) for an “evidentiary hearing” and “did not afford a reliable determination of the voluntariness of the confession [to be] offered in evidence at trial.” Jackson, 378 U.S. at 377.
That passage was subsequently cited for the idea that “opinions of our appellate courts are replete with precatory admonitions that trial judges must not function as partisans or advocates,” State v. Johnnie Carprue, 2004 WI App 111, ¶44 (court declining, however, to find that judge in that case crossed the line). Jiles’ conviction was plea-based; remedy for the tainted suppression hearing, the court holds without discussion, is plea-withdrawal and “a new and sufficient Miranda-Goodchild hearing,” ¶49.