dissenting:
I respectfully dissent.
I.
When Sporleder was decided I dissented because, in my view, the use of a pen register does not implicate protectable interests under either the United States or Colorado Constitutions. I continue to believe that telephone users do not have a legitimate expectation. of privacy in the numbers they dial. See Smith v. Maryland, 442 U.S. 735, 99 S.Ct. 2577, 61 L.Ed.2d 220 (1979); People v. Sporleder, 666 P.2d 135, 144-48 (Colo.1983) (Erickson, C.J., dissenting). I also believe that, while the Colorado Constitution must ultimately be interpreted by the Supreme Court of Colorado, this court should not substantially depart from the decisions of the United States Supreme Court which interpret parallel language and provisions in the federal constitution involving the same or similar issues, without principled reasons for doing so. See State v. Lowry, 295 Or. 337, 667 P.2d 996 (1983) (Jones, J., specially concurring); Pollock, State Constitutions as Separate Sources of Fundamental Rights, 35 Rutgers L.Rev. 707 (1983).
In my view, when provisions of the Colorado Constitution closely parallel the federal constitution, or in areas in which state rules or statutes are enacted pursuant to or closely dovetail federal acts or policies, the decisions of the United States Supreme Court should be approached with deference. The area of electronic eavesdropping and wiretapping has been the subject of pervasive federal legislation. After extensive studies, Congress enacted Title III of the Omnibus Crime Control and Safe Streets Acts of 1968 (Title III), 18 U.S.C. § 2510 et seq., which regulates the interception of certain wire and oral communications by both federal and state officials.
The federal statute provides latitude for state legislatures to enact legislation that is consistent with and which furthers the policies of Title III, and Colorado’s statute governing electronic surveillance was in fact closely patterned after the federal act. See § 16-15-101 et seq., 8 C.R.S. (1978). While the federal act does not directly apply to pen registers, United States v. New York Telephone Co., 434 U.S. 159, 98 S.Ct. 364, 54. L.Ed.2d 376 (1977), federal authorities which explain or interpret the policies underlying the various aspects of wiretapping should nevertheless be afforded greater weight and deference by states whose laws on the subject are largely the product of, and are designed to implement, federal policies.
Federal pronouncements, of course, cannot be dispositive of state issues in areas that are not fully preempted by the federal government. The state’s own constitution, statutes, and policies provide adequate and independent grounds for legitimate diver-gencies from federal decisions. But this court should look only in exceptional circumstances to the state constitution when it elects to depart from precedent of the United States Supreme Court interpreting similar provisions of the federal constitution. A state court should attempt to carefully set forth reasons why it believes that state law or policy leads to a different result. See, e.g., Right to Choose v. Byrne, 91 N.J. 287, 450 A.2d 925 (1982) (divergence from Supreme Court precedent is justified because the text and history of the state constitution is more expansive *219than the federal constitution and due to a pre-existing body of state law); State v. Hunt, 91 N.J. 338, 450 A.2d 952 (1982) (Handler, J., concurring) (structural differences between state and federal constitutions, matters of particular state concern, and state traditions justify a different result under the state’s constitution).
II.
Given this court’s holding in Sporleder, I would nevertheless decline to apply the decision retroactively. In my view, the rationale of our decision in Charnes v. DiGiacomo, 200 Colo. 94, 612 P.2d 1117 (1980), does not necessarily extend to pen registers such that it is “a foregone conclusion that the rule of the later case applies in earlier cases, because the later decision has not in fact altered the rule in any material way.” United States v. Johnson, 457 U.S. 537, 549, 102 S.Ct. 2579, 2587, 73 L.Ed.2d 202 (1982). Pen registers do not implicate the same interests that are involved in the disclosure of bank records, which was at issue in Chames. As I stated by way of dissent in Sporleder:
The pen register does not record the content of any conversation; it only records the number dialed. We emphasized in Chames that the substance of the bank records sought was a protected interest, not the fact that there may or may not have been a financial transaction. The intrusion in Chames into the substance of a person’s economic life is much greater than the recording of telephone numbers which have been dialed.
666 P.2d at 147.
I view this case as falling squarely under Linkletter v. Walker, 381 U.S. 618, 85 S.Ct. 1731,14 L.Ed.2d 601 (1965). In Linkletter, the Supreme Court formulated a three-part test for resolving questions dealing with the retroactivity of new constitutional rules of criminal procedure. The test, as restated in Stovall v. Denno, 388 U.S. 293, 297, 87 S.Ct. 1967, 1970, 18 L.Ed.2d 1199 (1967), requires a consideration of (1) the purpose to be served by the new rule, (2) the extent of reliance by law enforcement authorities on the old standards, and (3) the effect on the administration of justice of a retroactive application of the new standards. See also People v. Walker, 666 P.2d 113 (Colo.1983).
As in IAnkletter, I believe the rule announced in Sporleder does not affect the truthfinding process. The information obtained by a pen register is a business record that is generated contemporaneously with the use of a telephone and is not likely to be unreliable.1 In addition, in the light of the differences between pen registers and the practices at issue in Chames, and the clear standards applicable to pen registers announced in Smith, the police could have reasonably relied upon the Supreme Court’s rule. In my view, the retroactive application of the new rule announced in Sporleder would not advance any of the policies underlying the exclusionary rule, and would only result in the suppression of relevant evidence. See Desist v. United States, 394 U.S. 244, 89 S.Ct. 1030, 22 L.Ed.2d 248 (1969).
I authorized to say that ROVIRA, J., joins me in this dissent.
. In the present case, the information obtained from the pen register was used only to form the basis for obtaining a warrrant.