(concurring).
I agree with the court that neither Minn.Stat. § 609.045 (2012) nor the Minnesota Constitution bar the prosecution of Castillo-Alvarez in the State of Minnesota. I write separately to explain why the court is incorrect in concluding that our decision in State v. Scales, 518 N.W.2d 587 (Minn. 1994), does not apply to the admission of Castillo-Alvarez’s unrecorded statement. However, because I conclude that the Scales violation here was not substantial, I concur in the result only.
I.
In Scales, we held that “all custodial interrogation ... shall be electronically recorded where feasible and must be recorded when questioning occurs at a place of detention.” 518 N.W.2d at 592. In the exercise of our “supervisory power to insure the fair administration of justice,” we further held that “suppression will be required of any statements obtained in violation of the recording requirement if the violation is deemed ‘substantial.’ ” Id. The purpose of our rule in Scales “was to prevent factual disputes about the existence and context of Miranda warnings and any ensuing waiver of rights” by requiring an objective record of custodial interrogations. State v. Miller, 573 N.W.2d 661, 674 (Minn.1998); see also State v. Robinson, 427 N.W.2d 217, 224 n. 5 (Minn.1988) (explaining that “disputes arising from an accused’s claim of denial of constitutional rights could be obviated if police interrogators would record all conversations with the accused relative to the accused’s constitutional rights”).
On appeal, Castillo-Alvarez argues that the district court’s admission of his out-of-state unrecorded interrogation by federal and Iowa law enforcement officials was a substantial violation of Scales. As a threshold issue, we must consider whether the Scales requirement applies to Castillo-Alvarez’s unrecorded statement given that the statement was taken outside of Minnesota. In reaching the conclusion that Scales does not apply in this case, the court relies on defective reasoning.
With respect to procedural conflicts of law, we have traditionally held that the law of the forum (lex fori) controls. Davis v. Furlong, 328 N.W.2d 150, 152-53 (Minn. 1983) (explaining that the common law rule *541of lex fori dictates that “matters of procedure and remedies were governed by the law of the forum state”). However, the court departs from our precedent and concludes that the “most significant relationship” approach governs the determination of whether Scales applies to Castillo-Alvarez’s unrecorded statement. The court reasons that this case is analogous to State v. Heaney, in which we applied the “most significant relationship” approach to determine whether the Minnesota or Wisconsin physician-patient privilege rules applied to the admissibility of blood-alcohol evidence obtained in Wisconsin. 689 N.W.2d 168, 172-78 (Minn.2004). The court emphasizes that this case is similar to Heaney in that the physician-patient privilege and the Scales requirement each have a procedural and substantive purpose.
But the court’s reliance on Heaney is misplaced. In Heaney, we emphasized that privileges are created to “substantively protect a particular type of relationship deemed valuable to society in general” and therefore “hold a unique place in the law.” 689 N.W.2d at 174. We justified application of the “most significant relationship” approach based on the fact that privileges are “[ujnlike other rules of evidence that are concerned solely with the reliability of evidence.” Id. But here, the Scales requirement was created solely for the purpose of increasing the reliability of evidence. See Scales, 518 N.W.2d at 591 (explaining that a recording requirement ensures a “more accurate record of a defendant’s interrogation”). More importantly, the court ignores the fact that, with respect to evidentiary rules, the “most significant relationship” approach we adopted in Heaney is only intended to apply to the narrow scope of choice-of-law questions pertaining to privileges.1 See Restatement (Second) of Conflicts of Law § 139 (1971) (“Evidence that is not privileged under the local law of the state which has the most significant relationship with the communication will be admitted ... unless the admission of such evidence would be contrary to the strong public policy of the forum.” (emphasis added)). For these reasons, Heaney does not support application of the “most significant relationship” approach in this case.
But aside from the court’s misplaced reliance on Heaney, the court’s conclusion that Scales is both a procedural and substantive rule is simply wrong. The Scales rule, while producing a substantive effect, is purely procedural. In Scales, we relied exclusively on our supervisory power in holding that all custodial interrogations must be recorded in order to be admissible in Minnesota state courts.2 Scales, 518 N.W.2d at 592. As we recently noted in State v. M.D.T., our inherent authority *542permits us to adopt rules necessary to the function of the court system. 831 N.W.2d 276, 280 (Minn.2013). It does not, however, permit us to create substantive rules that “enforce or restrain acts which lie within the executive and legislative jurisdictions.” Id. (citation omitted) (internal quotation marks omitted); see also Minn. Const, art. Ill, § 1 (explaining that “[n]o person or persons” of one branch of government “shall exercise any of the powers properly belonging to either of the others except in the instances expressly provided in this constitution”). And as a practical matter, if our supervisory power does not extend to acts within the executive branch, it surely does not extend to executive branch actions that take place in another jurisdiction. Thus, because Scales was a product of our supervisory power, it is not and could not be a substantive rule, in whole or in part, that governs the activities of law enforcement officials. To say otherwise would fly in the face of the constitutional limitations on our inherent judicial power and run afoul of separation of powers.3
As I see it, the Scales rule is a procedural rule that is akin to our power to create rules of procedure and evidence within courts of the State of Minnesota. See M.D.T., 831 N.W.2d at 284 (Stras, J„ concurring) (characterizing our “inherent authority” as “judicial power” granted to the judicial branch in Article VI, Section 1, of the Minnesota Constitution). The Scales rule does not prohibit or mandate conduct, even for law enforcement officials in Minnesota. It merely provides that if certain evidence is to be admitted in a judicial proceeding, certain procedures must have been followed in obtaining that evidence in order to ensure the reliability of that evidence and protect the integrity of the judicial proceedings. And because the Scales rule sets forth a procedural as opposed to a substantive protection, the Legislature cannot overrule it by statute.
To be sure, we have emphasized that Scales “discourages unfair and psychologically coercive police tactics.” Scales, 518 N.W.2d at 591; see also State v. Waddell, 655 N.W.2d 803, 811 n. 3 (Minn.2003) (stating that “criminal defendants are ... protected against coerced confessions by the recording requirement”). But simply because Scales has the substantive effect of discouraging coercive police tactics does not mean that it is a substantive rule. Indeed, our rules of procedure are often adopted with substantive policy considerations in mind. See, e.g., Minn. R. Evid. 407, comm. cmt. — 1989 (barring introduction of evidence of subsequent remedial measures “[biased on policy considerations aimed at encouraging people to make needed repairs”); Minn. R. Evid. 408 comm. cmt. — 1977 (barring introduction of offers for compromise in order to “encourage frank and free discussion to compromise negotiations and avoid the necessity for parties to speak in terms of hypotheti-cals”). That does not, however, make those rules substantive in nature for the *543purposes of a conflict-of-laws analysis.4
I also take issue with the court’s conclusion that “there is no strong Minnesota policy requiring application of the Scales rule” in this case. As I emphasized in State v. Sanders, 775 N.W.2d 883, 891 (Minn.2009) (Page, J., dissenting), the public policy underlying the Scales requirement — the prevention of factual disputes relating to custodial interrogations — applies with equal weight to interrogations that occur outside of Minnesota. Indeed, we have never limited our concern for a defendant’s rights solely to cases involving Minnesota law enforcement or events occurring solely within Minnesota.
In sum, because the Scales rule arises from our authority to create rules of procedure and evidence within courts of the State of Minnesota, it is a procedural rule. On that basis, I would apply the lex fori approach and conclude that Scales applies to the admission of Castillo-Alvarez’s statement in a Minnesota state court.5 -See Davis, 328 N.W.2d at 152-53.
II.
Whether the Scales violation requires suppression of Castillo-Alvarez’s statement turns on whether the failure to record the statement was a substantial violation of the Scales rule. Scales, 518 *544N.W.2d at 592; see also State v. Edrozo, 578 N.W.2d 719, 722 n. 3 (Minn.1998). This court determines whether a substantial violation occurred “after considering all relevant circumstances” bearing on sub-stantiality. Scales, 518 N.W.2d at 592. Factors relevant to determining whether a violation is substantial include: (1) the extent to which the violation was willful; (2) the extent to which the exclusion will tend to prevent future violations; (3) the extent to which the violation is likely to have influenced the defendant’s decision to make the statement; and (4) the extent to which the violation prejudiced the defendant’s ability to support his motion to suppress or to defend himself at trial. Id. at 592 n. 5.
Applying the factors here, I conclude that the failure to record Castillo-Alvarez’s statement was not a substantial violation of the Scales rule. First, I would conclude that the out-of-state law enforcement officials did not willfully violate the Scales rule in taking Castillo-Alvarez’s statement. I acknowledge that in State v. Miller we stated that a Scales “violation shall be deemed wilful regardless of the good faith of the individual officer if it appears to be part of the practice of the law enforcement agency.” 573 N.W.2d 661, 674 (Minn.1998) (citation omitted). But here, I would conclude that the violation was not willful because the officers from the Federal Bureau of Investigation and the State of Iowa who interrogated Castillo-Alvarez were preparing for a prosecution that was to take place in a jurisdiction outside of Minnesota (the State of Iowa). Therefore, unlike Miller, there is no practical reason why the officers here should have been aware of the Scales rule. Additionally, because there is no evidence that Minnesota law enforcement officials were involved in the investigation of Castillo-Alvarez at the time he was interrogated, the failure to record Castillo-Alvarez’s statement was not an attempt by Minnesota law enforcement to willfully circumvent the Scales rule. Second, because prosecution was contemplated in a forum other than Minnesota, this is not a case in which suppressing the evidence would deter future violations of Scales. Third, there is no evidence in the record that the lack of an electronic recording influenced Castillo-Alvarez’s decision whether to make a statement. The record indicates that Castillo-Alvarez understood his Miranda rights, voluntarily signed an acknowledgment of those rights, and agreed to be interrogated without a lawyer present. Finally, the fact that Castillo-Alvarez’s statement was not recorded did not prejudice his ability to support his motion to suppress or to defend himself at trial. This is because Castillo-Alvarez’s motion to suppress his statement is based solely on the fact that the statement was not recorded. Castillo-Alvarez does not assert that a Miranda violation occurred. See State v. Inman, 692 N.W.2d 76, 81 (Minn.2005) (“If it is undisputed that the Miranda warning was administered, or that the accused waived his or her right to remain silent, the lack of a recording creates no prejudice to the accused.”). For the foregoing reasons, I am convinced that the Scales violation here was not substantial because it was not “gross, wilful [or] prejudicial.” Scales, 518 N.W.2d at 592 n. 5.
III.
In conclusion, because the rule we adopted in Scales is procedural, it applies to any custodial interrogation sought to be admitted in a Minnesota court, regardless of where that interrogation occurs. However, because the Scales violation here was not substantial, the district court was not required to suppress Castillo-Alvarez’s statement. Therefore, I concur with the *545court’s decision to affirm Castillo-Alvarez’s conviction.
. The court cites to a variety of cases from other jurisdictions to support its assertion that the "most significant relationship" approach is applied to resolve choice-of-law questions unrelated to privileges. But the court fails to point to any case in which we have applied the “most significant relationship” approach to a choice-of-law question pertaining to an evidentiary rule other than privileges. Moreover, many of the cases cited by the court from other jurisdictions are distinguishable in that they do not involve application of evidentiary rules. Finally, and most importantly, the rationale underlying application of the "most significant relationship" approach is inapplicable here. The court emphasizes that the "most significant relationship” approach has gained popularity "because the traditional choice-of-law approach is difficult to apply when a rule is not purely procedural or purely substantive.” But here, we have no such problem because Scales is purely procedural.
. Notably, we explicitly refrained from deciding whether a defendant has a substantive right to a recorded custodial interrogation under the Due Process Clause of the Minnesota Constitution. Scales, 518 N.W.2d at 592.
. The court contends that "the source of our authority to write the Scales rule” is not at issue in this case, arguing instead that the Scales rule "has both a procedural and substantive purpose.” But the court ignores the critical distinction between the nature of the rule itself and the effect that the rule may have. Because Scales is a product of our supervisory authority to create evidentiary rules, it cannot be anything other than procedural for the purposes of a conflict-of-laws analysis. Moreover, the court’s citation to cases in which we have granted a new trial pursuant to our supervisory power misses the point. Those cases have no relevance here because they do not involve application of our supervisory power "to regulate and supervise the rules that govern the admission of evidence." State v. Obeta, 796 N.W.2d 282, 287 (Minn.2011).
. The court contends that, in determining whether a particular rule is procedural or substantive in resolving a choice-of-law question, we must look to the "purposes” of the rule as opposed to the source of authority from which the rule was created. According to the court, if the rule at issue has both a procedural and substantive purpose, the "most significant relationship” approach should be applied to resolve the choice-of-law question. But because evidentiary rules are commonly promulgated with substantive purposes in mind, courts will almost always be able to identify some substantive “purpose" or "effect” underlying a rule of evidence. Indeed, by cavalierly shifting the focus of our choice-of-law jurisprudence to the "purposes” of the rule in question, the court, in effect, overrules more than 100 years of precedent in the State of Minnesota applying the lex fori approach to choice-of-law questions involving evidentiary rules. See Davis v. Furlong, 328 N.W.2d 150, 153 (Minn.1983) ("This court has for many years followed the almost universal rule that matters of procedure and remedies were governed by the law of the forum state.”); Jones v. Chicago, St. P., M. & O. Ry. Co., 80 Minn. 488, 491, 83 N.W. 446, 447 (1900) ("It is a general rule that the admission of evidence and the rules of evidence are rather matters of procedure, than matters attaching to the rights of parties. Therefore they are governed by the laws of the country where the court sits. The law of evidence is the lex fori.” (citation omitted)).
. The court cites to our decision in State v. Lucas, 372 N.W.2d 731, 737 (Minn.1985), for the proposition that it is "preferable” to apply a doctrine other than lex fori to determine the admissibility of evidence obtained in another state. Relying on Lucas, the court states that we have “made the pivot away from the lex fori " doctrine. Two points are worth noting. First,. the court points to no authority in which we have overruled the lex fori doctrine. Second, Lucas is not controlling here. Notably, in Lucas, we applied the exclusionary rule instead of the "most significant relationship" approach to resolve a conflicts-of-law question pertaining to the admissibility in a Minnesota court of a telephone statement recorded in Wisconsin. Id. But as the court readily concedes, the exclusionary rule is inapplicable when, as here, there was neither (1) conduct by police that was illegal under the statutes or constitutions of either the forum jurisdiction or the jurisdiction in which the statement was taken, nor (2) any statute or constitutional principle in the jurisdiction in which the statement was taken that would make the evidence inadmissible. Indeed, because the failure to record Castillo-Alvarez’s statement is not illegal under the statutes or constitutions of any of the relevant jurisdictions involved, including Minnesota, this is not the context in which we have said it is "preferable” to apply a doctrine other than lex fori. Given that our precedent dictates that the exclusionary rule and the "most significant relationship” approach are inapplicable here, lex fori controls.