Utah’s attorney general appeals from a final order of the Seventh Judicial District Court holding unconstitutional an act entitled Subpoena Powers for Aid of Criminal Investigation and Grants of Immunity (“Subpoena Powers Act” or “Act”). Utah Code Ann. §§ 77-22-1 to -3 (1982). The Act creates a second method for formally investigating criminal activities in addition to the already authorized state grand jury. It provides the attorney general and county attorneys with the power to subpoena witnesses, grant transactional immunity, and conduct investigations in secret, all with limited judicial supervision.
Beginning in 1983, the attorney general used the powers conferred by the Act to conduct an investigation into alleged criminal activities involving security operations at Utah Power and Light Company (“UP & L”). The investigation led to the filing of criminal charges. The respondents in this appeal are various individuals and companies that challenged subpoenas issued to them during the investigation. The district court dismissed the criminal investigation, ruling that the Act is facially unconstitutional and was unconstitutionally applied because it fails to provide for adequate judicial review to protect against abuse of power, is too vague, and fails to protect rights of due process and privileges against self-incrimination.
We agree that the Act was unconstitutionally applied and affirm the dismissal of the UP & L investigation. However, we reverse the lower court’s ruling that the Act is facially unconstitutional because we find that the Act is subject to an interpretation incorporating a number of substantive and procedural safeguards which bring the Act into constitutional compliance.
I. The Subpoena Powers Act
The Subpoena Powers Act was passed in 1971 upon a legislative determination that there had been “a marked increase in crime and criminal activity within this state.” Utah Code Ann; §§ 77-45-19 to -21 (1971). As amended and recodified in 1980, the Act’s purposes are to
grant subpoena powers in aid of criminal investigations and to provide a method of keeping information gained from investigations secret both to protect the innocent and to prevent criminal suspects from having access to information prior to prosecution and to clarify the power ... to grant immunity from prosecution to witnesses....
Utah Code Ann. § 77-22-1 (1982). The express provisions of the amended Act1 allow *637the attorney general and county attorneys (hereinafter referred to conjunctively as “state’s attorneys”), upon a showing of good cause, to receive approval from a district court for carrying out a criminal investigation. Once an investigation is approved, the state’s attorney may, without additional court authorization, subpoena witnesses to testify or produce other evidence, where such evidence “may be relevant to the investigation in the judgment of the attorney general or county attorney.” Id. at § 77-22-2(1).
The only notice expressly required to be given to a subpoenaed person is of the time and place of the interrogation, that it is “in aid of criminal investigation,” and that he or she has a right to counsel. Id. at § 77-22-2(2). There is no express provision that those served with subpoenas must be notified of any right to challenge the subpoena, of a privilege against self-incrimination, or of a right to have further information about the nature of the investigation.
The Act allows any district court, upon written application of the state’s attorney, to impose secrecy orders excluding nonessential persons from “any investigative hearing or proceeding” and requiring that the interrogation of any witness be held in secret and that the record of “such proceeding be secret.” Id. at § 77-22-2(3). The secrecy orders are to remain in effect until the court for good cause directs otherwise. Section 77-22-3 gives state’s attorneys the power to grant transactional immunity to witnesses2 and provides a con*638tempt procedure for compelling testimony from a person who refuses to comply “on the ground that he may be incriminated thereby.”
II. The UP & L Investigation
On January 26, 1983, Judge Bunnell of the Seventh Judicial District Court in Emery County, on application by the attorney general, authorized the investigation of criminal activities pursuant to the Subpoena Powers Act. The scope of the investigation was set forth in a good cause affidavit, signed by a special agent of the attorney general, that accompanied the application. The affidavit stated that on the basis of a confidential report prepared by the Utah Department of Business Regulation’s Division of Public Utilities, interviews with unnamed sources, and an investigation of UP & L, the affiant had concluded that certain of UP & L’s assets had been stolen. The affidavit described the stolen assets as UP & L’s labor and materials. The affidavit further alleged that the theft of these assets had been accomplished by kickbacks, payoffs, bid-fixing, falsification of shipment and delivery information, personal use or sale of UP & L property, and threats.
After determining that the statutory requirement of “good cause” to conduct an investigation had been shown, the district court authorized the attorney general to begin the criminal investigation. The court further authorized the attorney general to issue subpoenas compelling the attendance and sworn testimony of witnesses and the production of books, records, and other tangible items that constitute evidence “which is or may be relevant or material” to the investigation. Finally, the district court ordered that the Act's secrecy provision should apply to the record, to the “proceedings” of the investigation, and significantly, to the good cause affidavit!
Pursuant to this grant of authority, the attorney general’s staff issued numerous subpoenas during 1983 and 1984. According to the attorney general, the majority of the subpoenas were directed to banks, state agencies, and other document repositories. In addition, the attorney general directed subpoenas to each of the respondents to this appeal: UP & L, certain officers and employees of UP & L,3 Emery Mining Corporation, which operates UP & Lis coal mining properties, and individuals associated with companies, as well as the companies, that provided security services to UP & L.4
Each of the subpoenas stated that it was “authorized by order of the District Court” and that “[disobedience to this order is punishable by contempt of Court.” None of the subpoenas issued described the nature or scope of the investigation, nor were any of the respondents informed as to the general subject matter of the attorney general’s investigation. None of the respondents were informed that they were targets of the investigation. Some were told prior to their interrogation or production of documents that they had the right to exercise their privilege against self-incrimination. During the course of the investigation, the attorney general instructed witnesses that the secrecy provisions of the Act prohibited their speaking to anyone other than their counsel about the proceedings.
In April of 1984, the State filed criminal bribery, racketeering, and antitrust charges, as well as civil antitrust claims, against UP & L’s former corporate security officer and individuals associated with the security service companies, alleging that they had unlawfully secured contracts for security services between those companies and UP & L. The criminal investigation authorized by the district court continued after these charges were brought.
The following month, UP & L and certain officers and employees of UP & L, all *639respondents here, filed motions for protective orders and motions to quash subpoenas. Respondents argued that the Subpoena Powers Act is unconstitutional on its face and as applied. They maintained that the Act is vague, permits unreasonable searches, and violates witnesses’ privileges against self-incrimination because it does not provide for adequate disclosure to subpoenaed witnesses concerning whether they are targets of the investigation and the nature of the matter being investigated. They further claimed that the attorney general was misusing his authority to conduct a criminal investigation by issuing subpoenas under the Act for purposes actually related to civil discovery.
At a May 30, 1984, hearing on these motions, the district court denied the motion to quash. The court ruled that the Act would be presumed constitutional provided that the prosecutors (i) inform subpoenaed witnesses whether they were targets of the investigation, (ii) inform targets of the nature and scope of the matter under investigation, and (iii) conduct the investigation within the parameters of the good cause affidavit. Finally, the district court instructed the state’s attorneys not to use the information obtained under the Act for purposes of civil discovery.
In June, the criminally and civilly charged respondents moved to quash subpoenas directed to them, arguing that the subpoenas were overly broad and that it was improper to issue them once formal charges had been filed. Other respondents moved the district court to, inter alia, reconsider its May 30th ruling upholding the Act’s constitutionality. They contended that the district court’s imposition of procedural safeguards as a condition to the Act’s continued use constituted an impermissible judicial rewriting of the statute. Moreover, they argued that newly discovered legislative history showed that the district court’s interpretation of the Act’s procedural requirements did not accurately reflect the underlying legislative intent. In response to these motions, the attorney general withdrew all outstanding subpoenas except one directed to Emery Mining.
In August, Emery Mining moved to quash that subpoena. The district court granted Emery Mining’s motion to quash and agreed to reconsider the Act’s constitutionality. On September 20, 1984, the court held that the Act was unconstitutional on its face and as applied. Reasoning that the Act is vague, that it violates witnesses’ rights to due process and to exercise their privileges against self-incrimination, and that it fails to provide for adequate judicial supervision of the prosecutor’s subpoena powers, the court dismissed the criminal investigation.
III. Arguments on Appeal
On appeal, the attorney general concedes that the Act was unconstitutionally applied in the UP & L investigation. However, he argues that the district court erred in holding the Act unconstitutional on its face. He claims that the Act provides sufficient checks on the subpoena powers of the attorney general and the county attorneys to protect against any tendency toward prose-cutorial abuse. He argues that the Act contains sufficient procedural safeguards to protect against the denial of a witness’s fundamental rights to due process and to exercise the privilege against self-incrimination and that any flaws can be repaired through judicial interpretation.
Respondents 5 disagree with the attorney general’s position concerning the Act’s facial constitutionality, arguing that the Act’s failure to expressly provide for judicial control over the investigation permits the state’s attorneys unfettered discretion. Respondents also assert that the Act lacks *640adequate procedural protections to preserve a subpoenaed witness’s constitutional rights. In particular, they argue that witnesses should be informed of the nature of the matter under investigation and warned when they are targets of the investigation. They also argue that the Act’s lack of record-keeping requirements and the ill-defined secrecy provisions further obfuscate a witness’s opportunity to protect him- or herself from prosecutorial abuses. Respondents additionally attack the Act on the ground that it violates equal protection concepts embodied in the uniform operation of the laws provision of the Utah Constitution, article I, section 24, because it provides potential defendants with fewer procedural protections than does the state grand jury act. Finally, respondents assert that even if this Court were to find the Act constitutionally adequate, the district court’s order of dismissal should still be affirmed because the Act was applied unconstitutionally during the UP & L investigation.
IV. Analysis
A. Facial Constitutionality
It is a well-established rule that legislative enactments are endowed with a strong presumption of validity and will not be declared unconstitutional unless there is no reasonable basis upon which they can be construed as conforming to constitutional requirements. Greaves v. State, 528 P.2d 805, 806-07 (Utah 1974). In evaluating constitutional challenges to statutes, the Court looks to “reasonable or actual legislative purposes” rather than to “any conceivable reason for the legislation,” Malan v. Lewis, 693 P.2d 661, 671 n. 14 (Utah 1984), and will construe statutes to “effectuate the legislative intent” while avoiding interpretations that conflict with relevant constitutional mandates. State v. Casarez, 656 P.2d 1005, 1008 (Utah 1982); Zamora v. Draper, 635 P.2d 78, 80 (Utah 1981). Still, a court’s “interpretation [of a challenged statute] must be based on the language used, and ... the court has no power to rewrite a statute to make it conform to an intention not expressed.” Mountain States Tel. & Tel. Co. v. Public Serv. Comm’n, 107 Utah 502, 505, 155 P.2d 184, 185 (Utah 1945). Moreover, a court will exercise stricter scrutiny in evaluating measures that encroach upon civil liberties than it will with respect to statutes that impact what can be characterized as only economic interests. Allen v. Trueman, 100 Utah 36, 57, 110 P.2d 355, 365 (Utah 1941) (Wolfe, J., concurring); see also In re Boyer, 636 P.2d 1085, 1088 (Utah 1981); cf. Malan v. Lewis, 693 P.2d at 670-73; Berry v. Beech Aircraft Corp., 717 P.2d 670, 678-79 (Utah 1985).
In light of these precepts, we have concluded that the Subpoena Powers Act is subject to a constitutional construction.6 As set forth in detail below, we have interpreted the Act in accordance with the requirements of several federal and state constitutional provisions which provide the basis for a sensible interpretation of the Act and allow us to give it practical effect. See Greaves v. State, 528 P.2d at 807.
We have implied into the Act a number of procedural protections. Although a *641court cannot supply substantive terms that are absent from a statute, Kennecott Copper Corp. v. Anderson, 30 Utah 2d 102, 105, 514 P.2d 217, 219 (1973), it not only may, but must supply omitted procedural elements that are necessary to implement legislation consistent with constitutional requirements. See Carlson v. Bos, 740 P.2d 1269, 1276 (Utah 1987); In re Boyer, 636 P.2d 1085, 1088 (Utah 1981); Farris v. Cannon, 649 P.2d 529, 531 (Okla.1982); see also State v. Ruggeri, 19 Utah 2d 216, 222-25, 429 P.2d 969, 972-75 (1967); Baine v. Beckstead, 10 Utah 2d 4, 347 P.2d 554 (1959); cf. State in re Clatterbuck, 700 P.2d 1076, 1081 (Utah 1985) (supervisory authority over judicial procedures).
1. Judicial Supervision
The present version of the Subpoena Powers Act expressly requires, as respondents note, rather minimal supervision of an investigation. The Act provides only that the district court may authorize a criminal investigation upon a good cause showing, invoke the secrecy provisions, if requested, and limit those who may attend the proceedings. Utah Code Ann. § 77-22-2 (1982). Before the Act was amended in 1980, however, the district court had greater supervisory powers. Under the 1971 Act, the court did not authorize an entire investigation and then step away; instead, “upon application ... and for good cause shown,” it authorized the prosecutor to issue a particular subpoena. Utah Code Ann. § 77-45-20 (1971). Thus, under the prior Act, the district court engaged in preissuance approval of each subpoena, which would have provided it with an opportunity to judge the subpoena’s relevance to the investigation without requiring a motion to quash. The 1971 Act also provided, with respect to secrecy, that the interrogation of a witness could be performed before a “closed court.” Id. In the 1980 amendment, the reference to interrogation before a court was deleted and replaced with a provision that interrogations could be held “in secret.” These amendments were enacted without debate as part of a general recodification of the Utah Code of Criminal Procedure. To the extent that any legislative intent can be gleaned from the amended Act itself, we agree with respondents that the legislature did aim to limit judicial involvement in the criminal investigation. However, we think that those limitations are within constitutional bounds.
Respondents argue generally that the Act’s failure to mandate more judicial supervision and control over the investigation violates the federal fourth amendment prohibition against unreasonable searches and seizures7 and our state constitution’s separation of powers provision, article V, section 1. With respect to their fourth amendment claim, respondents assert that the Act provides witnesses with no effective means of obtaining precompliance judicial review of subpoenas. As a result, prosecutors will have unfettered discretion to subpoena anyone or anything they wish. Such discretion permits the state’s attorneys to unreasonably compel testimony and evidence, thereby violating privacy interests protected by the fourth amendment. Respondents also contend that conferring this unrestricted discretion on the state’s attorneys violates the separation of powers doctrine by vesting judicial subpoena powers in the hands of an executive branch officer.
The attorney general argues that adequate judicial supervision exists because the court has power to limit the scope of the investigation and, despite the lack of an express provision in the Act, also has au*642thority to review the reasonableness of subpoenas challenged by way of motions to quash.
The fourth amendment prohibition against unreasonable searches and seizures protects both individuals, see, e.g., Katz v. United States, 389 U.S. 347, 353, 88 S.Ct. 507, 512, 19 L.Ed.2d 576 (1967), and corporations, Oklahoma Press Publishing Co. v. Walling, 327 U.S. 186, 205-06, 66 S.Ct. 494, 503-504, 90 L.Ed. 614 (1946), against arbitrary government intrusion through the exercise of subpoena powers. See v. City of Seattle, 387 U.S. 541, 544, 87 S.Ct. 1737, 1739-40, 18 L.Ed.2d 943 (1967). The fourth amendment is satisfied if the subpoenaed party is allowed “to question the reasonableness of the subpoena, before suffering any penalties for refusing to comply with it, by raising objections in an action in district court.” Donovan v. Lone Steer, Inc., 464 U.S. 408, 415, 104 S.Ct. 769, 773, 78 L.Ed.2d 567 (1984). Article V, section 1 of the Utah Constitution prohibits the legislative branch or the executive branch from taking over judicial functions. As long as the district court retains ultimate precom-pliance control over the enforcement of a subpoena issued pursuant to the Act, the judicial function is not delegated unconstitutionally to the executive branch. Cf. Allen v. Lindbeck, 97 Utah 471) 480, 93 P.2d 920, 924 (Utah 1939) (determination of probable cause is a judicial function which cannot validly be delegated to an affiant). Therefore, the lack of a preissuance approval requirement does not render the Act violative of the fourth amendment or Utah’s separation of powers provision if a subpoenaed party can adequately question the subpoena’s reasonableness once it is issued but before compliance.8 The question, then, is whether precompliance review is available under the Act.
The Act does not expressly provide for judicial review of individual subpoenas. By the same token, it says nothing about restraining the widely recognized inherent supervisory powers courts have over judicial processes. The courts’ inherent supervisory power is that which is necessary to protect the fundamental integrity of the judicial branch, and it may not be wholly delegated to a nonjudicial officer. See Utah Const, art. VIII, § 1, art. V, § 1. This power enables a court to ensure that the judicial process is not abused. See State ex rel. Cranford v. Bishop, 230 Kan. 799, 801, 640 P.2d 1271, 1273 (1982). This inherent judicial supervisory power applies not only in the context of civil cases, but also in criminal cases, see United States v. Benz, 282 U.S. 304, 306-07, 51 S.Ct. 113, 113-114, 75 L.Ed. 354 (1931); Thomas v. State, 566 P.2d 630, 637-38 (Alaska 1977) (sentencing court has inherent judicial power to reduce a sentence), in federal grand jury proceedings, see In re Grand Jury Proceedings, 486 F.2d 85, 93 (3d Cir.1973) (general rule that grand jury need not make a preliminary showing of the reasonableness of a subpoena did not prevent district court from imposing such a requirement as an exercise of its inherent power to supervise grand jury proceedings), and in state prosecutorial investigations, see State ex rel. Cranford v. Bishop, 230 Kan. at 801, 640 P.2d at 1273 (district court has inherent power to refuse to issue subpoenas). Absent an express provision attempting to restrict the authorizing court’s powers, we construe the Act as not interfering with the court’s exercise of inherent judicial power, and we conclude that the authorizing court has inherent authority to entertain motions challenging subpoenas and to *643quash subpoenas.9
But saying that a court authorizing the use of subpoenas has inherent authority to consider motions to quash them does not fully answer respondents’ challenges. The court’s quashal authority must be meaningful if constitutional concerns are to be satisfied. The Act contains two provisions that bear on this point. Section 77-22-2(1) provides that subpoenas may be issued for testimony or other evidence which “may be relevant to the investigation in the judgment of the attorney general or county attorney.” Respondents contend that the plain import of this provision is that the state’s attorney alone is to decide whether a subpoena seeks relevant evidence. They assert that this limits the authorizing court’s review of a subpoena to a mere determination of whether the state’s attorney exercised good faith in issuing the subpoena and that such a limitation deprives the court of any power to review the subpoena under a standard of objective reasonableness. This, they argue, violates the state separation of powers provision, the fourth amendment’s search and seizure clause, and the void for vagueness doctrine of the fourteenth amendment’s due process clause.10 We do not agree that this provision of the Act limits the courts’ powers of review.
Our conclusion is guided by two rationales. First, the authorizing court has inherent authority to review subpoenas under a standard of objective reasonableness. We do not find the relevant provisions of the Act to be an express or even an implied attempt to deprive the court of that authority. Rather, it merely permits state’s attorneys to proceed with investigations without requiring that they return to the court for each separate subpoena. Second, the portion of section 77-22-2(1) that permits issuance of subpoenas based on the state’s attorney’s judgment of relevance must be read in light of the other provisions of the Act. Section 77-22-2(1) also provides that “the attorney general or any county attorney shall have the right, upon application and approval of the district court, for good cause shown, to conduct an investigation.” The only plausible reason for requiring a good caulb showing is to limit the scope of the authorized investigation accordingly. That provision would be meaningless if the state’s attorneys were allowed to issue subpoenas based solely on their subjective determination of relevance without regard to whether that judgment bore any objective relation to the scope of the court’s authorization for the investigation.
Accordingly, we conclude that an investigation conducted under the Act must proceed as follows: First, the overall inves*644tigation may be approved only after the district court has made an objective determination that “good cause” has been shown.11 Second, each individual subpoena may be issued only after the investigating attorney has made a good faith determination that the testimony or other evidence being sought is reasonably relevant to the authorized investigation. Third, a person to whom a subpoena has been issued must be afforded an opportunity to challenge the subpoena at some time prior to compliance. The authorizing court has the power to entertain motions to quash and, upon motion, must quash any individual subpoena that does not meet an objective standard of reasonableness when measured against the good cause showing made in the application for investigation.12
In sum, we find that the district court’s express authority under the Act tío authorize a criminal investigation, along with its inherent authority to supervise each investigation to ensure that the judicial subpoena power is not abused, satisfies any constitutional concerns about the adequacy of judicial control over the state’s attorney’s criminal inquiry. We now turn to considering the Act’s procedural defects.
2. Procedural Safeguards
Respondents argue that the Act does not provide adequate protections for the privilege against self-incrimination and the due process right to present evidence and cross-examine witnesses. They also contend that the Act fails to ensure that adequate records of investigations will be maintained so that investigations can be supervised by the courts. Finally, they argue that there are inadequate limitations on the operation of the Act’s secrecy provisions. The attorney general argues that the right to counsel provided for in the Act is sufficient to assure that a witness’s fundamental rights will be protected. He also contends that other procedural safeguards can be supplied by judicial interpretation. We find that the constitutional concerns respondents raise are satisfied by our construction of the Act as incorporating a number of procedural safeguards,
a. Privilege Against Self-Incrimination
Relying on both the state and federal constitutions, respondents claim that per*645sons subpoenaed under the Act are entitled to assert a privilege against self-incrimination. They contend that the Act is constitutionally deficient because it lacks the procedural safeguards necessary to permit the effective exercise of the privilege. Specifically, they argue that the Act does not require investigators to notify subpoenaed persons of the following: the general scope of the investigation; the right to exercise their privilege against self-incrimination; their status as targets of the investigation; and the nature of the charges being contemplated against them.13
The first question is whether the privilege against self-incrimination is available to those subpoenaed. The Act does not specifically provide for the exercise of a privilege against self-incrimination. However, section 77-22-3, which provides a procedure for compelling testimony by court order, does refer to “a person [who] refuses to answer a question or produce evidence of any kind on the ground that he may be incriminated thereby.” The section provides that the state’s attorney may grant such a person transactional immunity and obtain a court order compelling his or her testimony. It further provides that the witness shall be immune if he or she complies with the order and “would have been privileged to withhold the answer given or the evidence produced by him except for this section.” These references clearly imply that the legislature assumed witnesses subpoenaed under the Act would be able to claim a privilege against self-incrimination. We think this assumption was correct. Both the state and federal constitutions appear to require that persons subpoenaed under the Act have the right to assert the privilege against self-incrimination. The fifth amendment to the United States Constitution provides, “No person ... shall be compelled in any criminal case to be a witness against himself....” Article I, section 12 of the Utah Constitution states, “In criminal prosecutions the accused ... shall not be compelled to give evidence against himself....” These provisions grew out of a shared Anglo-American legal history. See M. Berger, Taking the Fifth: The Supreme Court and the Privilege Against Self-Incrimination (1980) [hereinafter Berger]; L. Levy, Origins of the Fifth Amendment: The Right Against Self-Incrimination (1968); 8 Wigmore, Evidence § 2250 (McNaughton rev. 1961); Corwin, The Supreme Court’s Construction of the Self-Incrimination Clause, 29 Mich.L.Rev. 1 (1930); Pittman, The Colonial and Constitutional History of the Privilege Against Self-Incrimination in America, 21 Va.L.Rev. 763 (1935) (hereinafter Pittman]. Both provisions have been interpreted broadly to incorporate the common law understanding of the right to remain silent. Ullmann v. United States, 350 U.S. 422, 450-53, 76 S.Ct. 497, 513-15, 100 L.Ed. 511 (1956) (Douglas, J., dissenting); American Fork City v. Crosgrove, 701 P.2d 1069, 1072-73 (Utah 1985). To the extent that the common law defines the privilege, the federal and state provisions have been interpreted similarly.14
Although both the federal and Utah constitutions refer to the availability of the privilege in the context of criminal cases, under both the privilege has been held to be available in any proceeding conducted by the government, civil or criminal, investigatory or adjudicatory, so long as an answer might incriminate the witness and a possibility exists that a criminal action might be filed or a criminal conviction secured. In re Gault, 387 U.S. 1, 47-48, 87 S.Ct. 1428, 1454-55, 18 L.Ed.2d 527 (1967); First Fed. Sav. & Loan Ass’n v. Schamanek, 684 P.2d 1257, 1261-62 (Utah 1984); Affleck v. Third Judicial Dist. Court, 655 *646P.2d 665, 666-67 (Utah 1982). On the basis of these precedents alone, we find that the privilege must be available in criminal investigations authorized and conducted pursuant to Utah’s Subpoena Powers Act. Indeed, the privilege’s availability may be even more critical in such investigations than in ordinary criminal trials. Not only are there fewer procedural protections during Subpoena Powers Act investigations, but the substantive standards may be lower than in ordinary criminal prosecutions. For example, section 77-22-2(1) of the Act permits the state’s attorneys to initiate an investigation “for good cause shown.” Although the present case does not present the question of precisely defining what that phrase means, on its face it appears that the Act may not require the same showing of probable cause that is necessary to bring a criminal charge, and the Act does not expressly require an allegation of any specific criminal violation, as is true of criminal informations and indictments, although there certainly must be some specificity to any “good cause” statement lest the Act tempt the state to poke “about in the speculation of finding something chargeable.” 8 Wigmore, Evidence § 2251, at 314 (McNaughton rev. 1961). This is an additional and independent reason for finding that the privilege against self-incrimination must be available in these circumstances.
We next consider the contours of the privilege in the context of a Subpoena Powers Act investigation. First, who may exercise the privilege? At common law, the privilege was available to witnesses as well as accused persons. Berger, supra p. 645, at 56. That is the interpretation given the fifth amendment, which states that “no person” shall be compelled to testify against himself. See, e.g., United States v. Mandujano, 425 U.S. 564, 96 S.Ct. 1768, 48 L.Ed.2d 212 (1976).
Article I, section 12 of the Utah Constitution is arguably narrower because it states only that “the accused” has the privilege. This could lead to the conclusion that article I, section 12’s protection was intended only for persons against whom charges have been brought or who have been identified. as targets of a criminal investigation. We reject that narrow interpretation and embrace the common law approach. All witnesses must be able to claim the privilege if the purposes of the privilege are to be satisfied — to protect those testifying from the risk of incriminating themselves. See, e.g., State v. Ruggeri, 19 Utah 2d 216, 222-23, 429 P.2d 969, 973 (1967) ordinary witness before state grand jury may claim the privilege, as may witness who has been identified as target).
The next issue is the scope of the privilege. We note several aspects, beginning with the question of whether a witness may remain completely silent or is privileged only to refuse to answer specific questions. Section 77-22-3 of the Act refers to the exercise of the privilege as a refusal “to answer a question.” We think that by using this language, the legislature indicated its intent that there be no general right to remain silent. Rather, the language shows an intent to require subpoenaed witnesses to answer all questions except those individual questions calling for an incriminating response. Although the parties here have not directly addressed this issue, we think it useful to briefly consider whether this interpretation of the statute will pass constitutional muster.
This interpretation does not appear to violate the fifth amendment’s protection of the privilege. The United States Supreme Court has held that although a criminal suspect has an absolute right to remain silent in a police custodial interrogation, see Michigan v. Mosley, 423 U.S. 96, 100-04, 96 S.Ct. 321, 324-26, 46 L.Ed.2d 313 (1975), and even though a criminal defendant may refuse to testify at all at his or her trial, see Allen v. Illinois, 478 U.S. 364, 366-369, 106 S.Ct. 2988, 2991-92, 92 L.Ed.2d 296, 303-04 (1986), a witness appearing before a federal grand jury “has an absolute duty to answer all questions, subject only to a valid Fifth Amendment claim” as to the particular question. United States v. Mandujano, 425 U.S. at 581, 96 S.Ct. at 1778-79 (plurality opinion). Given this holding regarding grand jury witnesses, it appears that the fifth amendment does not preclude *647a similarly limited scope of the privilege for Subpoena Powers Act witnesses.
Applying our state constitutional privilege, Utah Const, art. I, § 12, in State v. Ruggeri, 19 Utah 2d at 222-23, 429 P.2d at 973, we stated, “An ordinary witness before a [state] grand jury must give testimony except where it might incriminate him [or her] for some past misdeed_” Although the question we address here was not directly at issue in Ruggeri, and while we might find a broader scope for the privilege under other circumstances, for present purposes we think that this interpretation of the Act, which limits the privilege to specific incriminating questions, satisfies the requirements of our state constitution as interpreted in Ruggeri.
Several other aspects of the state and federal constitutionally based privileges should be noted. Despite differences in the language of the constitutional provisions, both privileges have been interpreted to apply only to testimonial or communicative disclosures. See, e.g., Schmerber v. California, 384 U.S. 757, 761, 86 S.Ct. 1826, 1830-31, 16 L.Ed.2d 908 (1966); American Fork City v. Crosgrove, 701 P.2d 1069, 1071-75 (Utah 1985).15 Moreover, both privileges have been held to apply to both oral and written communicative disclosures. See, e.g., Boyd v. United States, 116 U.S. 616, 633-35, 6 S.Ct. 524, 533-35, 29 L.Ed. 746 (1886); Crosgrove, 701 P.2d at 1076 (Stewart, J., concurring). But cf. Fisher v. United States, 425 U.S. 391, 408-14, 96 S.Ct. 1569, 1579-82, 48 L.Ed.2d 39 (1976). With respect to written disclosures, the fifth amendment privilege appears to be limited to private, personal papers. See Andresen v. Maryland, 427 U.S. 463, 474, 96 S.Ct. 2737, 2745, 49 L.Ed.2d 627 (1976). We have not considered a private-paper restriction under article I, section 12, but see Crosgrove, 701 P.2d at 1075-77 (Stewart, J., concurring), and because our decision does not depend on the outcome of that question, we do not reach it today. The federal privilege has virtually been restricted to natural persons, although the United States Supreme Court has not foreclosed the possibility that the privilege might protect some entities which may be closely aligned with individuals’ privacy interests. See Bellis v. United States, 417 U.S. 85, 101, 94 S.Ct. 2179, 2189-90, 40 L.Ed.2d 678 (1974); United States v. White, 322 U.S. 694, 64 S.Ct. 1248, 88 L.Ed. 1542 (1944). On the record before us, we decline to consider here whether article I, section 12’s privilege might be available to entities other than natural persons. However, we observe that the resolution of such questions will not necessarily follow the federal model. See note 14 supra.
Having canvassed the privilege, we now address respondents’ contention that the Act provides inadequate procedural safeguards to ensure that subpoenaed persons have a meaningful opportunity to exercise that privilege. No court has considered the procedures necessary to safeguard the privilege during an interrogation comparable to that contemplated by the Act. We find instructive, however, procedural rulings issued in the context of police custodial interrogations and grand jury investigations.
In Miranda v. Arizona, 384 U.S. 436, 444, 86 S.Ct. 1602, 1612, 16 L.Ed.2d 694 (1966), the Supreme Court ruled that to secure an individual’s fifth amendment privilege in a police custody setting, the individual must be warned prior to interrogation that (i) he or she has a right to remain silent, (ii) any statement made may be used as evidence against the individual, and (iii) he or she has the right to be represented by an attorney during interrogation, whether retained or appointed. However, when confronted with the ques*648tion of whether complete Miranda warnings need be provided to a federal grand jury witness, the Court answered “no.” United States v. Mandujano, 425 U.S. 564, 96 S.Ct. 1768, 48 L.Ed.2d 212 (1976) (plurality opinion). The Court found that the relatively less coercive atmosphere of a grand jury setting justified fewer protections than Miranda requires for police custodial interrogations. 425 U.S. at 579-80, 96 S.Ct. at 1777-78. However, the Court has not yet determined whether there are coercive elements in a grand jury setting sufficient to require some shorter form of warning pursuant to the fifth amendment. See id. 425 U.S. at 582 n. 7, 96 S.Ct. at 1779 n. 7; United States v. Washington, 431 U.S. 181, 188-89, 97 S.Ct. 1814, 1819-20, 52 L.Ed.2d 238 (1977); United States v. Wong, 431 U.S. 174, 97 S.Ct. 1823, 52 L.Ed.2d 231 (1977).
Turning to the Subpoena Powers Act, we conclude that interrogations conducted pursuant to the Act raise sufficient self-incrimination concerns that some form of warning is required if the privilege is to be meaningfully available. We think that an interrogation pursuant to the Subpoena Powers Act, though comparable in many respects to an appearance before a grand jury, is more coercive and thus raises greater self-incrimination concerns. Differences between the two investigative procedures give interrogations conducted pursuant to the Act a distinctly greater law-enforcement tone. In turn, the psychological compulsion facing a Subpoena Powers Act witness is greater than that which confronts a grand jury witness. For example, a Subpoena Powers Act interrogation is not conducted in the presence of a citizen panel, but before a prosecutor or a team of prosecutors and staff. In addition, it may be held “anywhere within the jurisdiction of the prosecutor,” including the prosecutor’s office. Utah Code Ann. § 77-22-2(2). To one interrogated in such a setting, with only the state’s investigators, a transcriber, and possibly the subpoenaed party’s attorney present, the psychological compulsion may be more analogous to that present in a police custodial inquiry, rather than one before a grand jury. Because the privilege is intended to protect against confessions secured by the sheer force of psychological intimidation, see generally 8 Wigmore, Evidence § 2251 at 314-17 (McNaughton rev. 1961); Berger, supra p. 645, at 31-35, we conclude that both the fifth amendment and article I, section 12 of the Utah Constitution16 mandate the procedural protections outlined below.
Although the coercive nature of a Subpoena Powers Act interrogation requires that some form of warning be given to preserve the right in a meaningful fashion, we do not think the exact warnings mandated by Miranda are sufficient or appropriate in the context of such a proceeding. For example, Miranda requires a warning that the person being interrogated has a right to remain completely silent. As discussed above, the Act does not require and we have not found that our state constitution mandates a right of complete silence in such interrogations, but only a right of silence as to specific questions which call for incriminating responses. Cf. United States v. Mandujano, 425 U.S. at 580, 96 S.Ct. at 1778 (no right of complete silence for grand jury witness).
Using the Miranda warnings as a general guide, we hold that to guarantee witnesses the privilege against self-incrimination under both the fifth amendment and, independently, article I, section 12 of the Utah Constitution, the state’s attorneys must notify every witness prior to interrogation (i) of the general subject matter of the investigation, (ii) of the existence and nature of the privilege against self-incrimination, (iii) that any information provided may be used against the witness in a subsequent criminal proceeding, and (iv) of the right to have counsel present. Relying only on article I, section 12 of the Utah Constitution, we add a further requirement that if a witness is the target of an investigation, he or she must be so informed prior *649to interrogation. These requirements warrant some discussion.
The first warning we require must inform the witness of the general subject matter of the investigation. No such requirement exists under Miranda. However, in a police custody setting, the person being interrogated almost certainly will know the nature of the crime being investigated, either because he or she has already been placed under arrest or because of precustodial questioning or events. This is not true in a Subpoena Powers Act setting. Under the Act, it is likely that no criminal charges will have been filed against anyone, nonsuspects may be questioned, and the witness may have no idea why he or she has been subpoenaed. Under such circumstances, we conclude that a witness will be in a position to exercise his or her privilege against self-incrimination only if first made aware of the general subject matter of the investigation by a statement from the state’s attorney couched in terms similar to those used in the good cause affidavit that provided a factual basis for the authorization of the investigation.
It may be argued that such a statement is unnecessary, because as explained below the application and supporting good cause affidavit specifying the nature of the investigation must be a matter of public record. A diligent witness could easily obtain the affidavit from the clerk of the authorizing court and inform him- or herself of the nature of the investigation. But we reject this line of reasoning. Such imputed notice will not suffice to protect the witness’s rights. The subpoena might not refer the witness either to the Act or to the good cause affidavit; therefore, few can be expected to know of their right to examine the affidavit. The only way that this interest can be adequately guaranteed is to require the state’s attorney to inform the witness of the subject matter of the investigation.
The second warning we require — that the subpoenaed person may refuse to answer any question or produce any evidence of a communicative nature that may result in self-incrimination — “is indispensable to ... insure that the individual knows that he [or she] is free to exercise the privilege” at any point during the proceeding. Miranda v. Arizona, 384 U.S. at 469, 86 S.Ct. at 1625. The third warning — that any information provided may be used against the individual in court — simply amplifies the second required warning by notifying the witness of the consequences of waiving the privilege. See id.
The fourth warning — that the witness may have counsel present — derives from Miranda and independently from the express terms of the Subpoena Powers Act, which requires that the subpoena itself notify a witness of his or her right to be represented by an attorney. Utah Code Ann. § 77-22-2(2) (1982). We think that this notice must be given again prior to any questioning of a witness. This restatement is necessary because the witness’s knowledge of his or her right cannot be presumed and because the witness’s view on whether he or she wants counsel present during the interrogation may change upon learning of the subject matter under investigation and of the possibility that any information provided may be used against the witness in a later criminal prosecution.
The fifth and final warning we construe the Act as requiring is applicable only to “targets” of the investigation. Such persons must be notified prior to questioning or the compelled production of evidence of their target status and of the nature of the charges under consideration against them. Respondents argue that such warnings are required by both the fifth amendment and our state constitution.
In United States v. Washington, 431 U.S. 181, 189, 97 S.Ct. 1814, 1819-20, 52 L.Ed.2d 238 (1977), the United States Supreme Court rejected an argument that the fifth amendment required target warnings in federal grand jury proceedings. The Court held that target warnings would “add nothing of value” in such proceedings because all witnesses, whether targets or not, were otherwise adequately protected from compulsory self-incrimination. Id. Washington may be distinguishable from the present case on its facts. The witness *650in Washington was undoubtedly aware of his target status, despite the investigators’ failure to give him notice. Id. And, as we have noted previously, grand jury proceedings such as those at issue in Washington are not as inherently coercive, for fifth amendment analysis, as interrogations under the Subpoena Powers Act. Nevertheless, the entire tone of Washington constrains us from finding that the federal constitution requires routine target warnings in the context of all Subpoena Powers Act interrogations.
The next question is whether, as a matter of state law, we will require target warnings. Article I, section 12 of the Utah Constitution is worded similarly to the federal fifth amendment. And, as we noted earlier, the state and federal privileges against self-incrimination share common-law roots. However, that fact does not necessarily require parallel construction. Differing state and federal experiences, concerns, and policy objectives may lead to differing interpretations of the two constitutional privileges in circumstances not addressed by the shared common law. The propriety of divergent construction has already been assessed with respect to the need for target warnings. Fully ten years before Washington, this Court ruled in State v. Ruggeri, 19 Utah 2d 216, 225, 429 P.2d 969, 975 (1967), that article I, section 12 requires that state grand jury witnesses be notified of their target status and of the charges being considered against them.17 At this time, we see no reason to reexamine our holding in Ruggeri, and we think that Subpoena Powers Act targets are similarly situated with respect to their privilege against self-incrimination as are state grand jury targets. Therefore, we hold that the target warnings required by Rug-geri must be given to Subpoena Powers Act targets,18 and we read such a requirement into the Act. Utah Const, art. I, § 12.
b. Rights to Present Evidence and Confront Witnesses
Respondents next contend that the Act denies them due process as guaranteed by the fourteenth amendment to the federal constitution because persons targeted for investigation are not provided an opportunity to confront and cross-examine adverse witnesses or to present evidence in their defense. They argue that such rights are necessary because of the accusatory nature of the proceedings. We conclude that such opportunities are not required because Subpoena Powers Act investigations are merely preliminary to the type of formal adjudicatory proceedings where such procedural guarantees are constitutionally required.
The fourteenth amendment prohibits the state from depriving investigation targets of “liberty” or “property” without due process. Respondents have not clearly defined the liberty or property interests that allegedly are at stake here. We assume that they refer to the infringement of liberty that would occur if the investigation ultimately led to a criminal conviction or to the injury to property that might result if an investigation were carried out publicly and led to a loss of employment or business opportunities. Assuming without deciding that some protected interest is at stake, we must determine what form of “process” is due under the fourteenth amendment and what procedural protections the state must afford one who is the potential target of a Subpoena Powers Act investigation.
In a series of cases, the United States Supreme Court has established a system of classifying agency proceedings and describing generally the type of safeguards required in each class of proceedings. These cases indicate that the requirements of due process vary depending on the nature and purpose of the proceeding and the likelihood that it will result in the deprivation of *651liberty or property. Hannah v. Larche, 363 U.S. 420, 440-42, 80 S.Ct. 1502, 1513-1515, 4 L.Ed.2d 1307 (1960). All proceedings fall into one of two major categories: adjudicative or investigative. Adjudicative proceedings are essentially judicial in nature and result in binding determinations that directly affect legal rights. The full panoply of procedural safeguards available in judicial proceedings are therefore available in adjudicative proceedings, including the rights to present evidence and cross-examine witnesses. See, e.g., Greene v. McElroy, 360 U.S. 474, 496, 79 S.Ct. 1400, 1413, 3 L.Ed.2d 1377 (1959); see also Morgan v. United States, 304 U.S. 1, 19-22, 58 S.Ct. 773, 776-778, 82 L.Ed. 1129 (1938); Ohio Bell Tel. Co. v. Public Util. Comm’n, 301 U.S. 292, 300-05, 57 S.Ct. 724, 728-31, 81 L.Ed. 1093 (1937); Southern Ry. Co. v. Virginia, 290 U.S. 190, 54 S.Ct. 148, 78 L.Ed. 260 (1933). On the other hand, investigative proceedings do not result in final determinations that directly affect legal rights, but only in findings presented for possible legislative or executive action.
A Subpoena Powers Act investigation does not result in any final determinations, rulings, or orders. Therefore, it does not qualify as adjudicative and must be investigative. However, that classification does not tell us what procedures due process requires, because the United States Supreme Court’s cases suggest three recognizable subcategories of investigative proceedings with different procedural demands. These subcategories are based on three rather distinct possible functions. Specifically, an investigative proceeding may (i) perform an accusative function, (ii) constitute a preliminary step to later adjudicative proceedings, or (iii) accomplish a legislative or executive fact-finding purpose. A Subpoena Powers Act investigation must be classified according to these subcategories before we can determine whether potential targets have the right to cross-examine witnesses and adduce evidence during the investigation.
An investigative proceeding is deemed to perform an accusative function if its purposes are (i) to find that certain persons are responsible for crimes or other prohibited acts and (ii) to expose or publicize the names of those persons. Jenkins v. McKeithen, 395 U.S. 411, 425-28, 89 S.Ct. 1843, 1850-51, 23 L.Ed.2d 404 (1969). Because such a proceeding effectively brands an individual a wrongdoer before the public without a trial, it is considered to be so closely, analogous to an adjudicative proceeding in terms of injury to the accused that a number of procedural protections must be provided, including the rights to present evidence and to cross-examine witnesses. Id. at 427-29, 89 S.Ct. at 1851-53.
The second analytical category of investigative proceedings includes those that function as information-gathering mechanisms that may be preliminary to a subsequent formal adjudicative proceeding. See, e.g., Anonymous Nos. 6 and 7 v. Baker, 360 U.S. 287, 291, 79 S.Ct. 1157, 1159-60, 3 L.Ed.2d 1234 (1959). The full procedural safeguards appropriate in adjudicative or accusative investigative proceedings are not required in preliminary investigative proceedings because the affected party will have a full opportunity to defend against any charges with all procedural protections in any subsequent adjudication and because such safeguards likely would unduly hinder the investigation. Hannah v. Larche, 363 U.S. at 446, 80 S.Ct. at 1516-17; In re Groban, 352 U.S. 330, 332, 77 S.Ct. 510, 512-13, 1 L.Ed.2d 376 (1957).
The third category of investigative proceedings — those that perform a legislative or executive fact-finding function — includes proceedings conducted by agencies that find facts and, perhaps, make recommendations to other bodies, but do not take action directly affecting legal rights. Proceedings with such aims need not provide any of the procedural safeguards traditionally associated with the judicial process. Hannah, 363 U.S. at 442-46, 80 S.Ct. at 1514-17; see, e.g., Groban, 352 U.S. at 332, 77 S.Ct. at 512-13.
Realistically, many agency investigations do not fit neatly into one of these rather abstract categories. When faced with such a proceeding, the courts must evaluate the totality of the circumstances to determine the predominant character of the proceed*652ing before classifying it. See, e.g., Hannah, 363 U.S. at 442, 80 S.Ct. at 1514-15; Jenkins v. McKeithen, 395 U.S. at 427-30, 89 S.Ct. at 1851-53; Groban, 352 U.S. at 332-33, 77 S.Ct. at 512-13. Certainly, such an evaluation is not entirely objective, but the categories do provide a useful framework for a due process balancing analysis.
The question is, into which of these categories does a Subpoena Powers Act investigation fall? Having considered the function of the investigation in relation to formal criminal proceedings, the likelihood of injury to targeted persons caused by the investigation, and the burden that full procedural safeguards would place on the agency in question, we conclude that Subpoena Powers Act proceedings are most closely analogous to preliminary investigative proceedings. To elaborate, the Act is intended to supplement existing law enforcement mechanisms and to enable the state’s attorneys to gather sufficient evidence with which to initiate formal adjudicative criminal proceedings. Investigations under the Act do have an accusative tone to the extent that they may lead the state’s attorneys to find that named individuals are responsible for wrongdoing. However, that finding does not have final legal consequences; it only leads to the filing of criminal charges. In that respect, the state’s attorneys’ preliminary finding of wrongdoing is virtually indistinguishable from the same conclusion reached after an informal criminal investigation conducted without benefit of the Subpoena Powers Act procedural safeguards. And the declared purpose of the Act — to keep investigations secret — clearly indicates that the Subpoena Powers Act investigation does not have the purpose of advertising the names of those who the state’s attorneys may conclude are wrongdoers. See Utah Code Ann. § 77-22-1 (1982).
It is true that investigations under the Act are not mere legislative fact-finding proceedings. They do have some impact on constitutionally protected liberty and property interests because their obvious and declared purpose is to aid in criminal investigations. The likelihood that criminal prosecution will follow an investigation justifies some procedural safeguards. But so long as the names of subpoenaed persons or targets are not publicized — and the Act contemplates that they will not be — the likelihood of injury to a protectible interest of the investigated party is not as high as that which exists in accusative proceedings and is no greater than that which attends general criminal investigations.19 In these circumstances, we find that the due process balance is satisfied if targets and other witnesses are provided the safeguards we have already discussed — the right to counsel, the privilege against self-incrimination, notice of these rights and of the nature of the investigation, and target warnings.20 We reject respondents’ claims that they should be afforded the rights to present evidence and cross-examine witnesses during the investigation. Such rights would prolong and complicate the investigative process, unduly hindering the state’s ability to uncover and prosecute crimes, without conferring any significant benefit on the investigated person that would not be provided at a preliminary hearing if charges were filed. Those rights are unnecessary at the investigative stage so long as they are afforded later. Cf. Utah Code Ann. § 77-11-4 (1982) (grand jury not bound to give target opportunity to present exculpatory evidence).
*653c. Record-Keeping Requirements and Secrecy Provisions
Respondents also contend that the Act requires only limited record keeping and allows far-reaching secrecy orders. This, respondents assert, violates the fourth amendment because the lack of a sufficient record and the operation of the secrecy provisions will make effective precompliance challenges to subpoenas impossible. Respondents also claim that the secrecy provisions are void for vagueness under the fourteenth amendment’s due process clause. Finally, respondents argue that the secrecy provisions encourage investigators to engage in forum shopping in violation of our state due process provision. Utah Const. Art. I, § 7. We conclude that the Act is subject to a reasonable interpretation which dispels respondents’ constitutional concerns.
We first address the claim that the Act does not contemplate the keeping of adequate records.21 It is true that the Act does not include a provision expressly referring to a requirement that records of investigations be kept. However, the Act does contain references which suggest that the legislature fully anticipated detailed record-keeping. Section 77-22-2(1) requires the state’s attorneys to make application, including a showing of good cause, in order to receive court approval for an investigation. Section 77-22-2(2) refers to the issuance of subpoenas. Section 77-22-2(3) requires a written application for a court order of secrecy. Section 77-22-3 requires a written application for a court order compelling testimony from a person to whom transactional immunity has been granted. These references, as well as others in the statute, make it clear that the legislature presumed a written record would be kept of every investigation conducted under the Act. This conclusion is bolstered by the legislature’s inclusion of extensive secrecy provisions which would have very limited value if there were no written records to be kept secret. It is also supported by the requirement that a complete record be kept of the somewhat analogous secret grand jury proceedings. See Utah Code Ann. §§ 77-11-9(4), (6) (Supp. 1987).
There is an additional, and perhaps stronger, reason why an official record of a Subpoena Powers Act investigation must be maintained. At the heart of the Act is the use by state’s attorneys of subpoenas issued under authority of district courts. The courts have inherent authority to supervise the use of this process for the purpose of assuring that it is not abused. Utah Const. Art. VIII, § 1, Art. V, § 1. See discussion supra part IV.A.1 of this opinion. To exercise this authority effectively, the courts must have access to a complete record of the investigation. Similarly, any appellate court that may review rulings of a district court on matters relating to the investigation must have available to it a complete record of the legal and factual context of the district court’s ruling.
In light of (i) the legislature's apparent intent that a full record of the investigation be kept, (ii) the need to ensure that authorizing courts have sufficient information to effectively exercise their inherent supervisory power over their process and to determine the merits of challenges to the conduct of the investigation, and (iii) the appellate courts’ requirement of an adequate record, as a matter of statutory construction and in the exercise of our inherent supervisory power over the judicial branch, e.g., In re Clatterbuck, 700 P.2d 1076, 1081 (Utah 1985), we conclude that all investigations must be fully documented and such documentation shall be maintained by the district court authorizing the investigation.
*654At this time, we cannot determine with precision what documentation will be necessary in each investigation conducted under the Act. However, the operation of the statute and the needs of the supervising courts dictate that the following be among the documents that form the permanent record of any investigation: (i) the application for authorization to commence an investigation, together with the supporting good cause statement; (ii) all motions made to the court; (iii) all orders of the court concerning the investigation, including the original order authorizing the investigation and any orders modifying its scope or duration; (iv) copies of all subpoenas issued; (v) detailed descriptions of all documents or other evidence produced in response to subpoenas;22 (vi) copies of all transcripts of testimony prepared; and (vii) all communications between the state’s attorneys or their staffs and the court.
The need for these items of information is apparent. For example, unless the good cause statement is preserved, as well as any other orders concerning the investigation’s scope and duration, there will be no way for a court to judge whether the state's attorney is exceeding the scope of his or her authority. Moreover, absent such a record, the recipient of a subpoena would have no way to judge its propriety. In a similar vein, unless the investigators’ use of the court’s subpoena power is fully documented by copies of subpoenas,23 transcripts of testimony,24 and documents produced, the court would have no way to supervise that use effectively. Finally, in the absence of a record of all communications between the state’s attorney and the court and of all actions sought from and orders entered by the court, it would be impossible for an appellate court to consider whether the district court was properly supervising the use of its subpoena powers. The foregoing provides sufficient record-keeping requirements to enable the Act to pass constitutional muster and to ensure a proper supervisory role for authorizing courts.
Respondents also challenge the constitutionality of the Act’s secrecy provisions. Section 77-22-2(3) of the Act provides that the investigating attorney
may make written application to any district court and the court may order that interrogation of any witness shall be held in secret; ■ that such proceeding be secret; and that the record of testimony be kept secret unless and until the court for good cause otherwise orders. The court may order excluded from any investigative hearing or proceeding any persons except the attorneys representing the state and members of their staffs, the court reporter and the attorney for the witness.
Respondents read these provisions broadly as giving the state’s attorneys vast power to conduct investigations outside judicial constraints. This power, they assert, is inconsistent with the requirements of state and federal due process. U.S. Const, amend. XIV; Utah Const, art. I, § 7. They also argue that the scope and operation of the secrecy provisions are so poorly defined that the Act fails to provide the courts or *655the state’s attorneys with even minimal guidance and, therefore, the provisions are so vague that they deny due process.
We agree with respondents that the statutory language could be more precise. Nevertheless, nothing in the statute warrants the broad construction that respondents have set up as a “straw man” against which to mount their attack. We find that the Act is subject to a construction sufficiently definite to weather an attack for vagueness and sufficiently narrow to prevent other due process violations, while ensuring adequate secrecy to satisfy the Act’s declared purpose of “keeping information gained from investigations secret both to protect the innocent and to prevent criminal suspects from having access to information prior to prosecution.” Utah Code Ann. § 77-22-1 (1982).
Section 77-22-2(3) specifically limits those things that may be kept secret to (i) the “interrogation of any witness,” (ii) “such proceeding,” and (iii) “the record of testimony.” This section also permits the court to exclude certain persons from “any investigative hearing or proceeding.” Despite respondents’ concerns that this section provides for wide-ranging secrecy orders, we think that these provisions are relatively narrow and largely self-explanatory. This section permits the district court to order that any witness 25 may be interrogated in secret, that all unnecessary persons may be excluded, and that the transcript of the interrogation may be kept secret. The only uncertainty is the meaning of the provision that “such proceeding” may also be kept secret. Read in context, this certainly does not mean that the district court can order everything about the investigation kept secret; rather, it means that the “proceeding” which constitutes the interrogation of a witness may be kept secret.26 To fulfill the purposes of the Act, an order of secrecy regarding “such proceeding” would necessarily include a bar on revealing the very fact that a particular interrogation will occur or has occurred, the substance of the evidence obtained, and the identity of the witness. Such information has great potential for damaging the reputations of innocent persons and may aid suspected criminals in hindering the investigation by intimidating witnesses or tampering with evidence. See KUTV, Inc. v. Conder, 635 P.2d 412, 413-14 (Utah 1981).
If a secrecy order is to effectively conceal information of the type described above concerning an interrogation, it may be broad enough to cover all potential sources of such information. Some of the sources that come readily to mind are documents in the hands of the court and of participants in the investigation, including state's attorneys, court reporters, court personnel, investigating agency staff, and other persons who have access to investigation documents or are present in interrogations. Those persons may be ordered not to reveal information about the investigation other than to participants whose knowledge is directly necessary for the conduct of the investigation. Cf Fed.R. Crim.P. 6(e)(2) (secrecy of grand jury proceedings). However, to avoid an interpretation of the Act that might raise constitutional questions, we construe the secrecy *656provisions as not preventing those subpoenaed from revealing facts concerning their own involvement in the investigation, including the fact that they have testified and the substance of that testimony. Cf id. In Subpoena Powers Act investigations, as in the federal grand jury context, imposing gag orders on witnesses “seems an unnecessary hardship and may lead to injustice.” Id. advisory committee’s note.
A further question remains. Once a secrecy order issues, does it apply to any and all interrogations, or does it apply only to particularly identified interrogations? We certainly think that the Act contemplates that the district court is empowered to cloak every interrogation with a secrecy order when adequate reasons for doing so exist. Yet we also think that the lack of historical precedent for allowing secret, non-grand jury inquisitions justifies a narrow interpretation of the Act, requiring that the state’s attorney apply for and that the court issue a secrecy order with respect to each individual interrogation. And we further conclude that the state must make a showing justifying such a secrecy order with respect to each interrogation for which secrecy is sought. Such a showing could be made only by demonstrating a reasonable likelihood that publicly releasing information about the identity of a witness or the substance of the evidence resulting from a subpoena or interrogation would pose a threat of harm to someone or otherwise impede the investigation. This requirement assures that the secrecy provisions may be used to serve their underlying purposes, but may not be used to indiscriminately conceal criminal investigations from public view.
We next note what may not be kept secret under the Act. The legislature tailored the secrecy provisions to protect only the interrogation or evidence-gathering proceedings; it clearly did not intend them to cover the application for the order authorizing the investigation or the state’s good cause showing. It is certainly possible that such a showing could be specific enough to guard against pretextual use of the Act by prosecutors and to permit meaningful supervision of the use of its subpoenas by the district court without identifying specific witnesses or targets. Therefore, the legislature may have concluded that permitting public access to the good cause showing would not necessarily raise the specter of harming the innocent or permitting criminal suspects to obstruct the investigation. Therefore, we conclude that the legislature’s omission of the showing in its list of information that may be made secret was intentional and that the application, good cause affidavit, and authorization order may not be kept secret.
We now address respondents’ claim that the Act’s secrecy provisions and lack of record-keeping provisions will prevent a subpoenaed person from learning enough about an investigation to protect his or her fourth amendment rights effectively.27 It is certainly true that a subpoenaed person must have a meaningful opportunity to challenge the lawfulness of a subpoena. Donovan v. Lone Steer, Inc., 464 U.S. 408, 415, 104 S.Ct. 769, 773, 78 L.Ed.2d 567 (1984). But in light of the construction we have given the Act’s secrecy provisions and record-keeping requirements, we find this claim to be without merit. The order authorizing the investigation and any order modifying that original order will be matters of public record, along with the supporting good cause statement. These should provide adequate information about the nature and scope of the investigation for a subpoenaed person to judge intelligently whether the subpoena may be subject to challenge. In the absence of a showing that public access to these documents will not permit adequate defense of fourth amendment rights, we find respondents’ claim entirely speculative.
Respondents further challenge the Act’s secrecy provisions on the ground that they will encourage the state’s attorneys to forum-shop, in violation of the Utah due process clause. Utah Const, art. I, § 7. The gist of this argument is that because *657the Act may permit judicial orders concerning an investigation to be kept secret from the public and other courts, a state’s attorney whose investigation has been limited in scope by one court’s order will be encouraged to commence another investigation before another district court that may be more favorably disposed toward the state’s position. Because each court will be unaware that the other has authorized an investigation, the state’s attorney can pick and choose among the judges’ rulings on similar points.
Our construction of the Act’s provisions largely eliminates such fancied infirmities. Nothing in the Act prevents the second court from being made aware of the existence of the first investigation. The initial application and authorizing order may not be kept secret. And any subpoenaed person is free to inform the second court of any information known to that person regarding the first investigation. We therefore conclude that the Act creates no greater risk of forum-shopping than is already present with other investigative methods. Respondents’ state constitutional due process challenge is without merit.
3. Equal Protection
Respondents next contend that the Subpoena Powers Act violates the equal protection principles we have found to inhere in the uniform operation of the laws provision of our state constitution, art. I, § 24,28 by creating a system for investigating criminal activities which is separate from and unequal to the state grand jury system. Respondents make two claims. First, they assert that persons investigated under the Act are treated less favorably in that they are given fewer procedural protections than those investigated under the grand jury statutes, sections 77-11-1 to -11 of the Code. Second, they argue that allowing investigators to choose freely between the two investigative systems encourages arbitrariness offensive to constitutional principles. We reject both arguments.
First, it is true that some procedural distinctions exist between the two investigative systems. Our construction of the Subpoena Powers Act eliminates the constitutionally significant distinctions by requiring target warnings and notice of the privilege against self-incrimination.29 We conclude that so long as persons investigated or subpoenaed under authority of either statutory scheme are accorded due process, the differences between the two systems are not enough, standing alone, to rise to the level of a violation of article I, section 24. See State v. Sisneros, 137 Ariz. 323, 670 P.2d 721 (1983) (coexistence of two methods for initiating a felony prosecution does not violate equal protection clause of state constitution); State v. Clark, 291 Or. 231, 630 P.2d 810 (availability of dual systems for initiating prosecutions does not violate state or federal equal protection constitutional provisions), cert. denied, 454 *658U.S. 1084, 102 S.Ct. 640, 70 L.Ed.2d 619 (1981); accord United States v. Simon, 510 F.Supp. 232 (E.D.Pa.1981) (denial of a preliminary hearing following a grand jury indictment does not violate federal due process or equal protection). But cf. Hawkins v. Superior Court, 22 Cal.3d 584, 586 P.2d 916, 150 Cal.Rptr. 435 (1978) (denial of a preliminary hearing following grand jury indictment violates state equal protection clause).30
This does not resolve respondents’ second claim, which is that even if the two investigation systems may constitutionally coexist, the state’s attorney responsible for choosing which system to use for any particular inquiry must act within constitutional constraints. Respondents suggest that if a state prosecutor’s discretion is entirely unfettered, his or her decisions about .whom to investigate and which statutory scheme to use may be so arbitrary as to violate equal protection principles contained in the uniform operation of the laws provision. Utah Const, art. I, § 24.
We agree that the uniform operation clause does impose some constraints on a state’s attorney’s exercise of discretion. See United States v. Batchelder, 442 U.S. 114, 125 n. 9, 99 S.Ct. 2198, 2205 n. 9, 60 L.Ed.2d 755 (1979); cf. State v. Bishop, 717 P.2d 261, 265-66 (Utah 1986) (applying state and federal equal protection principles to sentencing provisions). However, in the absence of some showing that the prosecutor is classifying persons improperly, the mere existence of the discretionary power to select which mechanism to use does not offend the uniform operation of the laws provision of article I, section 24. See United States v. Simon, 510 F.Supp. 232, 235 (E.D.Pa.1981) (prosecutorial discretion to charge by information or indictment does not violate federal equal protection provision).
We have considered respondents’ other claims and find them to be without merit. We reverse the district court’s ruling that the Subpoena Powers Act is facially unconstitutional. As we have interpreted it and with the procedural protections we have imposed, we find that the Act survives constitutional scrutiny.31
B. Validity as Applied
As the attorney general concedes, the Subpoena Powers Act was improperly applied during the Emery County investigation into the “theft” of UP & L’s “assets.” We find that the Act was improperly applied in at least three respects.
First, each subpoena included a statement that it was “authorized by order of the District Court” and that “[disobedience to this order is punishable by contempt of Court.” These representations should not have been made. They misstated the law and might have improperly discouraged the recipients from challenging the subpoenas. The first representation may have led respondents to believe, quite justifiably, that the court had previously reviewed individual subpoenas for reasonableness and that it would be futile to attempt to challenge a subpoena. Under the Act, the district court had not reviewed *659and authorized individual subpoenas; rather, it had authorized the overall investigation.
The second representation implied that each subpoena had the authority of a court “order” and that “disobedience” of the subpoena could be summarily punished as contempt. In reality, the individual subpoenas were not court orders, and refusal to comply with a subpoena could not be punished as contempt until several procedural steps had been followed. First, as discussed at the beginning of this opinion, subpoenaed persons may challenge a subpoena by means of a motion to quash. Second, under our general contempt law, no finding of contempt could issue until, inter alia, the state’s attorney had informed the court of the failure to comply and the court had conducted a hearing and made written findings that the witness had wilfully refused to comply.32 To the extent that these misrepresentations discouraged respondents or other subpoenaed parties from exercising their right to challenge the subpoenas, they denied rights guaranteed by the Act and by the fourth amendment. U.S. Const, amend. IV.
The second aspect of the Act’s improper usage is the failure of the state’s attorneys to notify every respondent, prior to interrogation or production of evidence, of the general nature and scope of the investigation and of the right to exercise the privilege against self-incrimination. These failures violated respondents’ state and federal constitutional privileges against self-incrimination.33 Utah Const, art. I, § 12; U.S. Const, amend. V.
Finally, we find that the secrecy provisions of the Act were applied too broadly. The district court’s secrecy order was so expansive that it covered the good cause affidavit submitted in support of the initial application for authorization of the investigation. As stated previously in this opinion, the secrecy provisions of the Act were not intended to cover the initial application for authorization or the supporting good cause statement. Moreover, to the extent that the concealment of the good cause statement impeded the challenge of subpoenas or interrogations, it operated to deny rights against unreasonable search and seizure. U.S. Const, amend. IV.
For these reasons, we conclude that the district court acted within the proper scope of its discretion to control the investigation and prevent abuse of the courts’ subpoena powers when it terminated the UP & L investigation.
HALL, C.J., and HOWE and DURHAM, JJ., concur.. The full text of the Act as amended in 1980 follows:
77-22-1. It is declared, as a matter of legislative determination, that it is necessary to grant subpoena powers in aid of criminal investigations and to provide a method of keeping information gained from investigations secret both to protect the innocent and to prevent criminal suspects from having access to information prior to prosecution and to clarify the power of the attorney general and county attorneys to grant immunity from prosecution to witnesses whose testimony is essential to the proper conduct of a criminal investigation or prosecution.
77-22-2. (1) In any matter involving the investigation of a crime, the existence of a crime or malfeasance in office or any criminal conspiracy or activity, the attorney gener-. al or any county attorney shall have the right, upon application and approval of the district court, for good cause shown, to conduct an investigation in which the prosecutor may subpoena witnesses, compel their attendance and testimony under oath before any certified court reporter, and require the production of *637books, papers, documents, recordings and any other items which constitute evidence or may be relevant to the investigation in the judgment of the attorney general or county attorney.
(2) The subpoena need not disclose the names of possible defendants and need only contain notification that the testimony of the witness is sought in aid of criminal investigation and state the time and place of the examination, which may be conducted anywhere within the jurisdication [sic] of the prosecutor issuing the subpoena, and inform the party served that he is entitled to be represented by counsel. Witness fees and expenses shall be paid as in a civil action.
(3) The attorney general or any county attorney may make written application to any district court and the court may order that interrogation of any witness shall be held in secret; that such proceeding be secret; and that the record of testimony be kept secret unless and until the court for good cause otherwise orders. The court may order excluded from any investigative hearing or proceeding any persons except the attorneys representing the state and members of their staffs, the court reporter and the attorney for the witness.
77-22-3. In any investigation or prosecution of a criminal case, the attorney general and any county attorney shall have the power to grant transactional immunity from prosecution to any person who is called or who is intended to be called as a witness in behalf of the state whenever the attorney general or county attorney deems that the testimony of such person is necessary to the investigation or prosecution of such a case. No prosecution shall be instituted against the person for any crime disclosed by his testimony which is privileged under this action, provided that should the person testify falsely, nothing herein contained shall be construed to prevent prosecution for perjury.
If during the investigation or prosecution a person refuses to answer a question or produce evidence of any kind on the ground that he may be incriminated thereby, the attorney issuing the subpoena may file a request in writing with the district court in which the examination is being conducted for an order requiring that person to answer the question or produce the evidence requested. The court shall set a time for hearing and order the person to appear before the court to show cause, if any he has, why the question should not be answered or the evidence produced, and the court shall order the question answered or the evidence produced unless it finds that to do so would be clearly contrary to the public interest, or could subject the witness to a criminal prosecution in another jurisdiction. If the witness still refuses to answer or produce the evidence, he shall be guilty of contempt of court and punished accordingly. If the witness complies with the order and he would have been privileged to withhold the answer given or the evidence produced by him except for this section, that person shall not be prosecuted or subjected to penalty or forfeiture on account of any fact or act co-nerning [sic] which, he was ordered to answer or produce evidence except he may nevertheless be prosecuted or subjected to penalty for any peijury, false swearing or contempt committed in answering, failing to answer, or for producing or failing to produce any evidence in accordance with the order.
The powers specified in this chapter are in addition to any other powers granted to the attorney general or county attorneys.
. The immunity provisions are not at issue in the present case. We addressed the power to *638grant immunity in State v. Ward, 571 P.2d 1343 (Utah), cert. denied, 435 U.S. 1005, 98 S.Ct. 1874, 56 L.Ed.2d 386 (1977).
. Karl J. Stott, Orrin T. Colby, Jr., and Norman Maxfield.
. Michael C. Thompson, Bruce A. Conklin, Michael Ziemski, Patricia Thompson Bowman, Mike Thompson & Associates, Guardex, Alar-mex, and Vanguard, Inc.
. Each respondent or group of respondents has submitted an appellate brief and participated in oral argument before this Court. Although each emphasizes slightly different aspects of the alleged constitutional infirmities of the Subpoena Powers Act, all respondents share the same central concerns about its meaning and application. The district court has dismissed the investigative proceeding and has cancelled all outstanding subpoenas; thus, this opinion will have no unique effect on any of the respondents, regardless of their individual circumstances. Hence, we use the term "respondents” to refer without distinction to all respondents, and we ascribe to all of them the arguments of each.
. Although we accept the attorney general's argument that the Act can be interpreted constitutionally, we concede that we are reaching the limits of our institutional competence in doing so. As Justice Wolfe stated in his concurring opinion in Mountain States Tel & Tel Co. v. Public Serv. Comm’n, 107 Utah 502, 517-18, 155 P.2d 184, 191 (Utah 1945):
[Tjhere are cases where reasonable minds may differ as to the point where interpretation stops and judicial legislation begins. In those cases where a judge may conscientiously conclude that he is exercising his function of interpretation his opinion will attempt to reach, through interpretation, that result which accords with workability, practicality, common sense and justice. But where he does not think that reasonable minds could differ, as on the question of whether what we are asked to do is really legislation, it is his duty to stay within the province of the judiciary and restrain from invading the province of the legislature despite his personal longings for a different result.
Although the judiciary is capable of engaging in the type of reconstructive surgery we perform today, we recognize that the legislature should have incorporated many of the protections we imply into the statute. It could have done so at least as effectively as, and certainly more efficiently than, the judicial branch.
. Respondents do not support the search and seizure argument, however, with reference to the relevant Utah constitutional provision, article I, section 14. Several of respondents’ other arguments are based solely on references to federal constitutional provisions without reference to analogous state constitutional provisions. Consequently, in resolving such issues, we do not address the requirements of the state constitution. See State v. Lafferty, 749 P.2d 1239, 1247 n. 5 (Utah 1988); State v. Earl, 716 P.2d 803, 805-06 (Utah 1986).
Where state constitutional issues have been raised, we have so noted and have indicated that certain of our specific holdings are based on state constitutional grounds independent of federal constitutional provisions, in accord with Michigan v. Long, 463 U.S. 1032, 1040-42, 103 S.Ct. 3469, 3476-77, 77 L.Ed.2d 1201 (1983).
. We note that neither Utah’s Grand Jury Act, Utah Code Ann. §§ 77-11-4, -9 (1982 & Supp. 1987), nor a number of other state prosecutorial investigation statutes, see, e.g., Kan.Stat.Ann. § 22-3101 (1981); Del.Code Ann. tit. 29, § 2508 (1979), require preissuance approval of subpoenas. Nor is such approval required in the case of subpoenas issued by the Federal Trade Commission, see 16 C.F.R. § 2.7 (1987), or by the Internal Revenue Service, see 26 C.F.R. § 301.7602-1 (1987). Moreover, although a federal grand jury must apply to the court for its process, Fed.R.Crim.P. 17(a); United States v. Stevens, 510 F.2d 1101, 1106 (5th Cir.1975), there may be little practical difference between this prior, often perfunctory, judicial review and no judicial review at all at this stage. See In re Grand Jury Proceedings, 486 F.2d 85, 90 (3d Cir.1973); In re Credit Information Corp. of New York, 457 F.Supp. 969, 971 (S.D.N.Y.1978).
. Cf. Utah Code Ann. §§ 78-7-5, -17 (1987) (powers of courts), §§ 78-24-5 to -7 (subpoenas); Utah R.Civ.P. 45 (subpoenas). We emphasize that the court’s power to quash subpoenas inheres in the judiciary and is not founded on any particular statutory provision. It is true that rule 14(b) of the Utah Rules of Criminal Procedure expressly states that courts may quash or modify subpoenas if compliance would be unreasonable. This provision is qualified, however, by rule 14(a), which discusses subpoenas "to require the attendance of a witness or interpreter before a court, magistrate or grand jury in connection with a criminal investigation or prosecution." (Emphasis added.) A subpoena issued pursuant to the Act compels the attendance of a witness before a prosecutor. Therefore, a court’s rule 14(b) quashal authority does not appear to cover subpoenas issued during a criminal investigation conducted pursuant to the Act.
. Respondents base their vagueness argument on Kolender v. Lawson, 461 U.S. 352, 103 S.Ct. 1855, 75 L.Ed.2d 903 (1983). They ask that we apply the vagueness doctrine to the Act because, although it "focuses both on actual notice to citizens and arbitrary enforcement... the more important aspect of the vagueness doctrine ‘is ... the requirement that a legislature establish minimal guidelines to govern law enforcement.’” Id. at 357-58, 103 S.Ct. at 1858-59 (citation omitted). The attorney general contends that the vagueness doctrine has no application to a nonpenal statute such as the Act. Instead, he claims that the doctrine applies only to requiring that governments provide adequate notice of a law to individuals when sanctions may he imposed for misconduct and notes that despite Kolender's emphasis on "guidelines to govern law enforcement,” it concerned a criminal statute and its holding must be so limited. We need not reach this issue in the present action because we find that the Act is not sufficiently unclear to create a serious problem of interpretation, much less one of constitutional magnitude.
. Although the Act does not define "good cause," respondents do not challenge either the constitutional sufficiency of the statutory standard or the district court’s finding in the UP & L investigation that the standard was satisfied by the attorney general’s affidavit and application. Justice Stewart's dissent suggests that the "good cause" standard has so little substance that it leaves the state’s attorneys free to engage in wide-ranging investigations without effective judicial limitation. Although we do not have occasion today to reach the question of the precise definition to be given the term "good cause," we think it clear that the standard does not allow the initiation of an investigation on mere whim or pretext. While mere suspicion may be enough to institute a routine police investigation, it is clearly not enough to justify putting the judicial subpoena power into the hands of prosecutors, even with the protections we imply into the Act today.
. On the record before us, we do not attempt to define in detail the parameters of this objective standard of reasonableness. We note, however, that the reasonableness or relevance of a subpoena issued in the context of an investigation is measured by less exacting standards than one issued during the course of a trial. In re Grand Jury Investigation, 381 F.Supp. 1295, 1299 (E.D. Pa.1974); accord United States v. McKay, 372 F.2d 174, 176 (5th Cir.1967) (relevancy and materiality of subpoenas have broader connotations in the context of an administrative agency investigation than in a trial setting). This is true whether the investigation is conducted by a federal or state grand jury, an administrative agency, or a state’s attorney pursuant to the Subpoena Powers Act. For, regardless of the differences between those entities, each has "a legitimate right to satisfy [itself] that corporate [or individual] behavior is consistent with the law and the public interest.” United States v. Morton Salt Co., 338 U.S. 632, 652, 70 S.Ct. 357, 368-69, 94 L.Ed. 401 (1950) (administrative agency). And in so doing, the investigator may run down every available clue and examine witnesses in every proper way to discover whether the law has been violated. United States v. Stone, 429 F.2d 138, 140 (2d Cir.1970) (federal grand jury).
Of course a governmental investigation ... may be of such a sweeping nature and so unrelated to the matter properly under inquiry as to exceed the investigatory power.... But it is sufficient if the inquiry is within the authority of the agency, the demand is not too indefinite and the information sought is reasonably relevant.
United States v. Morton Salt Co., 338 U.S. at 652, 70 S.Ct. at 369.
. Respondents also argue that these procedural deficiencies violate the federal prohibition against unreasonable searches and seizures by preventing subpoenaed persons from effectively raising precompliance challenges. We do not reach that argument because our construction of the Act eliminates any such procedural defects.
. However, when contemporary questions outside the realm of the common law arise, differing federal and state sensitivities or policy objectives may result in different protections. Cf. State v. Earl, 716 P.2d 803, 805-06 (Utah 1986) (inviting argument on the differing scope of protection under the state and federal constitutional search and seizure provisions).
. Section 77-22-3 of the Act also refers to the privilege in the context of a refusal to "produce evidence of any kind.” This might be interpreted as an indication that the legislature intended to extend the privilege to evidence which is not communicative in nature. In Crosgrove, 701 P.2d at 1075, we held that the state constitutional privilege did not prevent the state from compelling a suspect to take a breathalyzer test. In view of our extensive discussion in that case and in the absence of further indication of legislative intent, we conclude that the privilege available in proceedings under the Act is limited to testimony and evidence of a testimonial or communicative nature. Utah Code Ann. § 77-22-3 (1982).
. We emphasize that this holding is based independently on our state constitution so as to eliminate any suggestion that we rely solely on the federal fifth amendment. See Michigan v. Long, 463 U.S. 1032, 1040-42, 103 S.Ct. 3469, 3476-77, 77 L.Ed.2d 1201 (1983).
. The target warning requirements of Ruggeri have since been codified, Utah Code Ann. § 77-11-3(2) (1982).
. We further note our disagreement with the United States Supreme Court’s suggestion in Washington that target warnings are worthless, and we observe that requiring warnings will not impose a significant burden on state investigators or impede legitimate inquiries.
. Our federal due process analysis might well differ if the state were to conduct an investigation in a highly public manner, contravening the Act’s declared purpose of secrecy to protect the innocent.
. Future abuses of the powers granted by the Act may, however, require that additional rights and warnings be given to subpoenaed persons. If we conclude after further experience that Subpoena Powers Act interrogations are as coercive as custodial police interrogations, subpoenaed persons who cannot afford to retain counsel would have to be accorded and notified of the right to appointed counsel. And even though this decision does not require the state’s attorneys to notify subpoenaed persons of their right to challenge subpoenas, experience may show that such a warning is necessary to meaningfully protect witnesses from governmental overreaching.
. A somewhat related question is respondents’ claim that the secrecy provisions of the Act mean that once a secrecy order is entered, virtually no record need be kept of an investigation. The secrecy provisions are discussed generally below. But it suffices on this point to observe that there is nothing in the Act that would support the conclusion that the secrecy provisions in any way relieve the court or the state’s attorneys of the obligation to maintain records of the investigation. The secrecy provisions operate only to limit those who may have access to the records that are maintained.
. The written description of documents, in most cases, would consist of a list of the documents and a brief description of the substance of each. This requirement is not intended to saddle the investigating agency or the authorizing court with a heavy burden of document management. The descriptions need only be sufficient to reasonably document the course of the investigation.
. Copies of subpoenas may be necessary, among other reasons, for court protection of targets who are unable to challenge subpoenas on their own. For example, a broad subpoena issued to a third party may invoke a target’s privacy interests. See, e.g., Tiffany Fine Arts, Inc. v. United States, 469 U.S. 310, 322, 105 S.Ct. 725, 732, 83 L.Ed.2d 678 (1985). Although under federal law it has been held that a target cannot challenge the investigation of a third party, SEC v. Jerry T. O'Brien, Inc., 467 U.S. 735, 741-42, 104 S.Ct. 2720, 2725, 81 L.Ed.2d 615 (1984), we have never addressed the question as a matter of state law.
.The requirement that copies of any transcripts of testimony be filed is closely analogous to the requirement in Utah Code Ann. § 77-11-9(5) that grand jury testimony be preserved. It will also facilitate review of the state’s attorneys’ compliance with the notice-to-witnesses requirements articulated elsewhere in this opinion.
. We assume that the Act was intended to cover not only the interrogation of witnesses giving oral testimony, but also the interrogation of those subpoenaed primarily for the purpose of obtaining documents or other items of real evidence in their control. Therefore, the secrecy provisions would apply equally to the fruits of either type of interrogation.
. Our interpretation of the scope of secrecy intended by the Act is supported by a comparison of the language of die 1971 and the 1980 versions of the statute. The 1971 Act provided that upon a state’s attorney's application, the court could order that the "interrogation of any witness shall be before a closed court; [and] that such proceeding be secret." Utah Code Ann. § 77-45-20 (1971). In 1980, the words "held in secret" were substituted for “before a closed court.” In the 1971 Act, the words "such proceeding” obviously related to the antecedent “interrogation of any witness ... before a closed court.” Although the current version of the Subpoena Powers Act clearly no longer requires that the district court directly oversee the specific interrogation which is to be conducted in secret, there is no indication that such a change also expands the scope of secrecy by cutting the words "such proceeding” loose from their former mooring.
. Respondents do not claim a denial of rights under the Utah constitutional provisions barring unreasonable searches and seizures. See note 7, supra.
. Respondents cite article I, section 2 of the Utah Constitution to support their equal protection claim. This Court has noted, however, that while article I, section 2 uses the term "equal protection," "it is more a statement of a purpose of government than a legal standard that can he used to measure the legality of governmental action." Malan v. Lewis, 693 P.2d 661, 669 n. 13 (Utah 1984). Article I, section 24 provides, "All laws of a general nature shall have uniform operation." In application, this section is considered the state equivalent of the equal protection clause of the fourteenth amendment to the United States Constitution. Malan, 693 P.2d at 669, n. 13 (citing Liedtke v. Schettler, 649 P.2d 80, 81 n. 1 (Utah 1982)). Because the substance of respondents’ equal protection claim remains unchanged regardless of its constitutional source, we analyze this argument under article I, section 24.
. The remaining procedural distinctions involve differences in the presence of a citizen panel and the right to a preliminary hearing. On balance, we find it difficult to say which investigative process is more advantageous to a subpoenaed person. For example, in grand jury proceedings, the coercive atmosphere of the interrogation is arguably lessened by the presence of the citizen panel. However, it has been observed that such citizen panels may be little more than rubber stamps for the prosecution. See, e.g., Hawkins v. Superior Court, 22 Cal.3d 584, 589, 586 P.2d 916, 919, 150 Cal.Rptr. 435, 438 (1978) and authorities cited therein. Also, if persons investigated under the Act are eventually charged, they are accorded a pretrial preliminary hearing with all of its protections, but persons indicted by a grand jury proceed directly to trial. Cf. id. 22 Cal.3d at 592, 586 P.2d at 921, 150 Cal.Rptr. at 440.
. In Hawkins, the California Supreme Court held that a defendant charged by indictment is seriously disadvantaged in contrast to a defendant charged by information. Using a state equal protection analysis, the court found that the state could offer no compelling interest for denying the fundamental rights inherent in a preliminary hearing to some while granting those rights to others. Thus, the court concluded that equal protection mandates that those indicted by a grand jury receive a post-indictment preliminary hearing. 22 Cal.3d at 592-95, 586 P.2d at 921-22, 150 Cal.Rptr. at 440-41. We think that the Hawkins court’s analysis actually merges the concepts of due process and equal protection and that the court ultimately imposed the requirement of a post-indictment preliminary hearing to satisfy its conception of due process.
. This is not to suggest that our finding of facial constitutionality will survive abuse of the Act’s powers. Both our analysis and our conclusion may change dramatically if future cases show that the powers are subject to practical abuse despite the procedural and substantive safeguards we have implied into the Act. And as our holding that the trial court properly terminated the UP & L investigation demonstrates, the courts must closely monitor any actual application of the Act’s provisions to determine whether the state’s attorneys have overstepped their bounds.
. See, e.g., Utah Code Ann. §§ 78-32-1 to -16 (1987); Thomas v. Thomas, 569 P.2d 1119 (Utah 1977); cf. Utah R.Civ.P. 37 (contempt for failure to cooperate in discovery). We do not intend this general overview to be an exclusive list of the substantive and procedural rules required for a finding of contempt for failure to comply with a subpoena issued under the Act. Nor do we imply that failure to comply with a subpoena issued under the Act without precompliance judicial review will necessarily be governed by the same standards as failure to comply with a subpoena which has been previously reviewed by a court.
We note also that in section 77-22-3 of the Act, the legislature has outlined certain procedures to be followed in determining whether failure to comply with a subpoena is contempt. The language defining the circumstances under which those procedures are required is ambiguous. Under one interpretation, the heightened procedural protections would apply only to witnesses who have been granted immunity; under another, they would apply to all persons subpoenaed under the Act. We need not reach that issue of statutory construction in this case because we hold that the representations on the face of the subpoenas misstated even the basic procedural requirements of our general law of contempt.
. The attorney general has represented to this . Court that none of the respondents were investigation targets; therefore, there was no failure to give the target warnings required by article i, section 12 of the Utah Constitution.