(dissenting). Because this court cannot determine from this record whether the defendant had a legitimate expectation of privacy in his communication on the telecommunications device for the deaf (TDD), I would remand the case for an evidentiary hearing on the defendant's suppression motion. After the circuit court holds the eviden-tiary hearing and makes findings of fact, the record *33should be forwárded to this court for decision about the defendant's legitimate expectation of privacy.
A legitimate expectation of privacy is, according to United States Supreme Court cases, an expectation that society is prepared to recognize as reasonable. Majority op. at 16. As Professor LaFave points out, this statement is tautological. The fourth amendment protects those interests that may justifiably claim fourth amendment protection. LaFave, Search and Seizure, sec. 2.1(d), p. 314 (2d ed. 1987).
The answer to the question of what interests justify fourth amendment protection is a value judgment a court makes based on the totality of circumstances. "This question must be . . . answered by assessing the nature of a particular practice and the likely extent of its impact on the individual's sense of security balanced against the utility of the conduct as a technique of law enforcement." United States v. White, 401 U.S. 745, 786 (1971) (Harlan, J. dissenting). See also majority op. at 16.1
*34Since Katz v. United States, 389 U.S. 347 (1967), courts have recognized that society regards the expectation of privacy in the contents of personal communications as legitimate, even when the communication is from a public telephone booth.
The defendant argues that his telephone conversation with Catherine Teeters should be accorded the same fourth amendment protection as if he had gone out of the sheriffs department and used a public telephone. He argues that neither his deafness — which requires him to use a special type of telephone — nor the fact that he was in the sheriff's department should affect his fourth amendment right to personal communications without government surveillance.
The state argues that while society may recognize a legitimate expectation of privacy in personal communications made in other situations, society does not recognize any privacy interest in communications made on the department's telephone, in the dispátch area, in the presence of a deputy sheriff.
Missing in this case is a record of the totality of the circumstances from which a court may balance the competing interests of the individual's privacy of conversation and the utility of the conduct of the law enforce*35ment officers in recording and keeping the record of the defendant's telephone conversation. The record is devoid of facts relating to communications involving the use of the TDD or any telephone located in the sheriffs department or particularly in the dispatch area.
Although sec. 971.31(4), Stats. 1987-88, requires that issues of fact raised by a suppression motion be decided by the circuit court without a jury and although the defendant made several requests for a hearing on his suppression motion, the circuit court did not grant a hearing. I think the circuit court erred in not holding a hearing.
Thus the record does not furnish adequate information about the operation of the TDD, the department's practice of monitoring incoming and outgoing conversations (of the hearing and the hearing impaired) on telephones located in the department or in the dispatch areas, and the needs of law enforcement to monitor telephone calls of both the hearing and hearing impaired who happen to be in the department but who are not under arrest. The record does not tell us, for example:
• whether the sheriffs department has any established policy about the use of the TDD;
• whether the sheriffs department routinely permits the hearing impaired to use the TDD;
« whether other TDD devices were readily available to the defendant outside the sheriffs department but in the vicinity of the sheriffs department;
• whether the defendant had used the department's TDD before June 9,1987;
• whether the defendant knew how to disengage the printer on the TDD so that no printed record of the conversation was made. The court of appeals' opinion assumed, without factual proof, that the defendant knew how to disengage the printer and decided not to do so. *36Court of Appeals, unpublished slip op. at 9 (Wis. Ct. App. Nov. 7, 1989);
• whether the sheriffs department regularly and customarily retains the TDD tape;
• whether the TDD had "a memory feature which recorded transmissions as well as producing the tape," majority op. at 19, although the majority opinion makes a finding of fact that the machine has such a memory feature;
• whether notices were posted in the sheriffs department near the telephone alerting users of the TDD (or any other telephone) about law enforcement officers' access to the conversations;
• whether calls placed to and from telephones in the dispatch areas are routinely monitored and recorded, although the state's brief, p. 36 and the majority op. at 21, conclude that they are;
• whether the sheriffs department had access to the telephone conversations of hearing persons using telephones in the department and whether the department treated telephone conversations of the hearing and of the hearing impaired in the same manner or in a different manner;
• why the sheriffs department recorded, if it did, conversations on telephones located in the department, including conversations made by members of the public who were not under arrest, and how the department used the recordings.
The state, the defendant, the majority opinion, and I agree that the court's decision on whether the defendant had a legitimate expectation of privacy must be based on the totality of the circumstances. Because the record is almost devoid of any of the "circumstances" needed to make a decision, I do not believe the court can *37decide whether the defendant had a legitimate expectation of privacy. I would therefore remand for a hearing.
The parties debate who has the burden of persuasion in this case. The state contends that this case involves both adjudicative and legislative facts. Adjudicative facts are ordinarily historical facts pertaining to the lawsuit; legislative facts ordinarily refer to the factual grounds for policy judgments. Adjudicative facts are generally proved in an evidentiary hearing. Legislative facts may be furnished the court through an evidentiary hearing or briefs or the court may obtain the facts on its own investigation of published sources. For discussions of adjudicative and legislative facts and the use of social science research, see sec. (Rule) 902.01, Stats. 1985-86; McCormick, Evidence, sec. 331 (3d ed. 1984), at 928; Walker and Monahan, Social Facts: Scientific Methodology as Legal Precedent, 76 Calif. L. Rev. 877 (1988); Walker and Monahan, Social Frameworks: A New Use of Social Science in Law, 73 Va. L. Rev. 559 (1987); Monahan and Walker, Social Authority: Obtaining, Evaluating, and Establishing Social Sci*34ence in Law, 134 U. Pa. L. Rev. 477 (1986); Davis, Facts in Lawmaking, 80 Colum. L. Rev. 931 (1980); Davis, Judicial, Legislative, and Administrative Lawmaking: A Proposed Research Service for the Supreme Court, 71 Minn. L. Rev. 1 (1986); Florida v. Riley, 488 U.S. 445, 465-66 (Brennan, J. dissenting).
The determinative legal issue, once the court has the adjudicative and legislative facts, is whether the facts meet the legal standard of legitimate expectation of privacy on the part of the defendant. The applicability of the burden of persuasion to deciding this question of law rather than to determining1 the facts is dubious.