concurring in the result:
I concur in the result reached in the main opinion. I write separately to explain how this decision affects the issues raised under our state constitution and to express my reservations in the treatment of the attenuation issue.
STATE CONSTITUTION ANALYSIS
I agree that the issues raised under our state constitution are moot. In so holding, we have necessarily resolved two important questions: First, we have rejected the primacy approach to state constitution analysis in this area of the law. Second, the state constitution analysis undertaken by the court of appeals is dictum.
I. Rejection of the Primacy Approach
The State argues this case under the state constitution, conceding that the roadblock violated the Fourth Amendment. Therefore, the only possible reason the State’s concession could render this ease moot is that we have looked first to the federal constitution. By holding that this case is moot, we have implicitly rejected the primacy approach to interpreting our state constitution. Under the primacy approach, we would look first to decide the issue under the state constitution; if the state constitution resolves the issue, we would not even consider the federal constitution. See Milo S. Marsden, The Utah Supreme Court and the Utah State Constitution, 1986 Utah L.Rev. 319, 326 (citing Hans *844Linde, Without “Due Process”, 49 Or.L.Rev. 125, 133 (1970)). Were we to apply the primacy approach in this case, the State’s concession under the federal constitution would be irrelevant unless we first held the search to be valid under the state constitution. This we have not done. We have therefore necessarily rejected the primacy approach in this case.1
II. Dictum
The court of appeals analyzed this case under both the federal constitution and the state constitution. See State v. Sims, 808 P.2d 141, 145-150 (Utah Ct.App.1991). Because we have held that the issues raised under the state constitution are moot, any discussion of the state constitution is unwarranted. The state constitution analysis undertaken by the court of appeals must therefore be considered to be mere dictum. See, e.g., Consolidation Coal Co. v. Emery County, 702 P.2d 121, 125 (Utah 1985) (language was dictum “in that it was not essential to the resolution of the issue in the case”).
ATTENUATION
The standard for deciding whether consent is sufficiently attenuated from the illegal stop was set forth by this court in State v. Thurman, 846 P.2d 1256 (Utah 1993). This standard requires consideration of three factors: “[1] ‘the purpose and flagrancy of the official misconduct,’ [2] the ‘temporal proximity’ of the illegality and the consent, and [3] ‘the presence of intervening circumstances.’ ” Id. at 1263 (quoting Brown v. Illinois, 422 U.S. 590, 603-04, 95 S.Ct. 2254, 2261-62, 45 L.Ed.2d 416 (1975)). Like most questions involving application of law to fact, attenuation should be decided in the first instance by the trial court. See State v. Pena, 869 P.2d 932, 937 (Utah 1994) (appellate court grants at least some discretion to trial court’s application of law to fact); State v. Barnhart, 850 P.2d 473, 475-77 (Utah Ct.App.1993) (same).
The roadblock in the present case occurred before roadblock standards under the federal constitution had been established. See Michigan Dep’t of State Police v. Sitz, 496 U.S. 444, 110 S.Ct. 2481, 110 L.Ed.2d 412 (1990). A trial court might therefore reasonably conclude, under the “purpose and flagrancy” prong, that defendant’s consent in the present case was attenuated from the illegal stop. Before Pena was decided, however, this court had already dispositively ruled on the attenuation question in Sims’s stop. See Sims v. State Tax Comm’n, 841 P.2d 6, 10 (Utah 1992). While I believe this court erred in deciding the issue of attenuation for the first time on appeal, the doctrine of res judi-cata prohibits us from now revisiting this question. See Salt Lake Citizens Congress v. Mountain States Tel. & Tel. Co., 846 P.2d 1245, 1251-52 (Utah 1992).
HALL, J., did not participate herein; BENCH, Court of Appeals Judge, sat.. Determining which analytical model we will utilize in interpreting our state constitution (primacy, interstitial, etc.) is fundamentally different from determining the substantive issues in a case. Our implicit rejection of the primacy approach is therefore not a determination on the merits of the substantive issues raised under our state constitution.