A17-0883

1
STATE OF MINNESOTA

IN SUPREME COURT

A17-0842
A17-0883

Court of Appeals Gildea, C.J.

Mark Jerome Johnson,

Appellant,

vs. Filed: August 22, 2018
Office of Appellate Courts
State of Minnesota,

Respondent.
________________________
Cathryn Middlebrook, Chief Appellate Public Defender , Veronica May Surges, Assistant
Public Defender, Saint Paul, Minnesota, for appellant.
Lori Swanson, Attorney General, Saint Paul, Minnesota; and
John J. Choi, Ramsey County Attorney, Adam E. Petras, Assistant Ramsey County
Attorney, Saint Paul, Minnesota, for respondent.
________________________
S Y L L A B U S
1. Appellant’s argument that the test -refusal statute, Minn. Stat. § 169A.20,
subd. 2 (2016), is unconstitutional as applied to him raises an issue of the district court’s
jurisdiction. Because the argument goes to the court’s jurisdiction, appellant’s guilty plea
did not waive his right to raise this argument.

2
2. Because the Supreme Court ’s decision in Birchfield v. North Dakota ,
579 U.S. ___, 136 S. Ct. 2160 (2016), and our decisions in State v. Trahan, 886 N.W.2d
216 (Minn. 2016), and State v. Thompson, 886 N.W.2d 224 (Minn. 2016), created a class
of people constitutionally immune from p unishment, the rule announced by these cases is
substantive and applies retroactively to final convictions on collateral review.
Reversed and remanded.
O P I N I O N
GILDEA, Chief Justice.
In this case we are asked to determine whether the Supreme Court’s decision in
Birchfield v. North Dakota , 579 U.S. ___, 136 S. Ct. 2160 (2016), and our decisions in
State v. Trahan, 886 N.W.2d 216 (Minn. 2016), and State v. Thompson, 886 N.W.2d 224
(Minn. 2016), announced a new rule of constitutional law that applies retroactively to cases
on collateral review. The district courts and the court of appeals concluded that the rule
was procedural and not retroactive. B ecause we conclude that the rule is substantive and
retroactive, we reverse.
FACTS
This consolidated appeal arises from two separate traffic stops. The first stop
occurred in 2009 , when St. Anthony police stopped appellant Mark Jerome Johnson on
suspicion of driving while impaired (DWI). After Johnson admitted that he had been
drinking and show ed signs of impairment, police arrested him. Police read Johnson the
Minnesota Implied Consent Advisory and asked him whether he would take a blood or a
urine test. Johnson refused. Respondent the State of Minnesota charged Johnson with

3
first-degree test refusal , Minn. Stat. §§ 169A.20, subd. 2 (2016), 169A.24 (2010).1
Johnson pleaded guilty on April 29, 2010 and was sentenced to a 48 -month prison term,
stayed for 7 years. Johnson did not file a direct appeal.
The second stop occurred i n 2014, while Johnson was on probation for his 2010
test-refusal conviction . P olice stopped Johnson for using his turn signal improperly.
Johnson admitted that he had been drinking, and he failed field sobriety tests. Police then
arrested Johnson for DWI and read him the Minnesota Implied Consent Advisory. Johnson
said that he wanted to contact an attorney. After affording Johnson time to call an attorney,
police asked if he was willing to cons ent to a chemical test for the presence of alcohol .
Johnson indicated that he had been advised by his attorney to refuse unless the officer had
a warrant. Police interpreted this as a refusal, and the State charged Johnson with first-
degree test refusal, Minn. Stat. §§ 169A.20, subd. 2 (2016), 169A.24 (2012). Johnson
pleaded guilty on April 23, 2015 and was sentenced to a 51 -month prison term and a
mandatory 5-year period of conditional release. Johnson did not file a direct appeal.
In December 2016, Johnson filed a consolidated petition for postconviction relie f
challenging his 2010 and 2015 convictions for test refusal. He argued that the Supreme
Court’s decision in Birchfield v. North Dakota, 579 U.S. ___, 136 S. Ct. 2160 (2016), and
our decisions in State v. Trahan , 886 N.W.2d 216 ( Minn. 2016), and State v. Thompson,
886 N.W.2d 224 (Minn. 2016), announced a new, substantive rule of federal constitutional

1 Johnson was charged with first-degree test refusal because, at the time, he had three
or more qualified prior impaired driving incidents within the last 10 years. See Minn. Stat.
§§ 169A.09, 169A.24 (2010); see also Minn. Stat. § 169A.24 (2012).

4
criminal law that was retroactively applicable to his conviction s on collateral review. 2
Under that rule , Johnson maintained that his convictions for refusi ng to submit to
warrantless blood and urine tests violated the constitution and must be vacated.
The district court considered the petition separately for each of Johnson’s prior two
convictions, with one judge hearing the petition for the 2010 test-refusal conviction, and a
different judge hearing the petition for the 2015 test-refusal conviction. Each district court
concluded that the Birchfield rule was procedural and did not apply retroactively to
Johnson’s conviction . Alternatively, each concluded th at by pleading guilty, Johnson
waived the right to challenge his conviction. Both courts summarily denied Johnson’s
petition.
Johnson appealed both district court decisions, and the court of appeals consolidated
the appeals. The court of appeals affirmed, concluding that the Birchfield rule did not apply
retroactively to Johnson’s final convictions because the rule was procedural in nature, and
accordingly, the district courts did not abuse their discretion by denying Johnson’s
postconviction petitions. Johnson v. State, 906 N.W.2d 861, 867 (Minn. App. 2018). We
granted Johnson’s petition for review.
ANALYSIS
This case comes t o us on appeal from decisions on Johnson’s postconviction
petition. We review the denial of a petition for pos tconviction relief for an abuse of

2 Both parties agree that these three holdings represent a single rule of law that
originated in Birchfield and our court applied in Trahan and Thompson. For simplicity, we
refer to the rule as the “Birchfield rule.”

5
discretion. Dikken v. State , 896 N.W.2d 873, 876 (Minn. 2017). We will reverse a
postconviction court if the court “ ‘exercised its discretion in an arbitrary or capricious
manner, based its ruling on an erroneous view of the law, or made clearly erroneous factual
findings.’ ” Brown v. State , 863 N.W.2d 781, 786 (Minn. 2015) (quoting Reed v. State ,
793 N.W.2d 725, 729 (Minn. 2010)).
On appeal, Johnson argues that the Birchfield rule applies retroactively. The State
contends that , because Johnson pleaded guilty, he waived his right to assert that the
Birchfield rule applies retroactively. If we reach the question of whether the Birchfield rule
applies retroactively, the State urges us to affirm. Specifically, the State contends that the
rule is procedural and therefore inapplicable to cases on collateral review.
Before addressing the parties’ arguments and to provide context for our analysis,
we turn first to a discussion of the Birchfield rule. In Birchfield v. North Dakota , the
Supreme Court consolidated three cases, each of which concerned whether criminal test -
refusal laws violated the Fourth Amendment prohibition against unreasonable searches.
579 U.S. ___, 136 S. Ct. 2160, 2170–72 (2016). Although the cases shared the same
general issue, two of them were based on the refusal of a blood test, and the other on the
refusal of a breath test. Id. The Court noted that in order to criminalize a suspected
impaired driver’s refusal of a warrantless search, the warrantless search must “comport
with the Fourth Amendment.” Id. at ___, 136 S. Ct. at 2172. It further held that a breath
test was a permissible search incid ent to a lawful arrest , but that a blood test did not fall
within this exception to the warrant requirement. Id. at ___, 136 S. Ct. at 2185.
Consequently, the State could make it a crime for a suspected impaired driver to refuse a

6
blood test only if the police ha ve a search warrant or a valid exception to the warrant
requirement applies. Id. at ___, 136 S. Ct. at 2185–86.
Following the Supreme Court’s decision in Birchfield, we decided State v. Trahan,
886 N.W.2d 216 (Minn. 2016), and State v. Thompson, 886 N.W.2d 224 (Minn. 2016). In
Trahan, the defendant was arrested on suspicion of DWI and refused to submit to a blood
test. 886 N.W.2d at 219. He was subsequently charged with and ple aded guilty to first-
degree test refusal. Id. at 219–20. In a postconviction petition filed after Trahan’s direct
appeal was stayed, he argued that the test-refusal statute was unconstitutional as applied to
him. Id. at 220. We applied Birchfield, holding that “the Fourth Amendment prohibits
convicting Trahan for refus ing the blood test requested of him absent the existence of a
warrant or exigent circumstances.” Id. at 221. We concluded that, because no exigent
circumstances existed, the test -refusal statute , Minn. Stat. § 169A.20, subd. 2, was
“unconstitutional as applied.” Id. at 224.
In Thompson, the defendant was convicted of second -degree test refusal after he
refused warrantless blood and urine test s. 886 N.W.2d at 227. We concluded that
“Birchfield is dispositive with respect to the blood test that Thompso n refused” and that
“[a] warrantless blood test may not be administered as a search incident to a lawful arrest
of a suspected drunk driver.” Id. at 229. We also held that a urine test was not a permissible
search incident to a lawful arrest. Id. at 233. The State did not argue that exigent
circumstances existed. Id. at 229 n.3. Accordingly, we determined that the test -refusal
statute was unconstitutional as applied to Thompson, and that he could not be “prosecuted
for refusing to submit to an unconstitutional warrantless blood or urine test.” Id. at 234.

7
In sum, the Court’s decision in Birchfield and our application of Birchfield in
Trahan and Thompson mean that, in the DWI context, the State may not criminalize refusal
of a blood or a urine test absent a search warrant or a showing that a valid exception to the
warrant requirement applies. With this description of the Birchfield rule in mind, we turn
to the parties’ arguments.
I.
We first consider whether, as the State argues, Johnson’s guilty p lea precludes him
from arguing that the Birchfield rule is retroactive. The State asserts that Johnson’s
argument is based on his Fourth Amendment right to be free from an unreasonable search.
And the State contends that by pleading guilty to test refusal, Johnson forfeited his right to
collaterally attack his convictions on that basis. For his part, Johnson argues that because
he was convicted under a statute that was deemed to be unconstitutional as applied, the
district courts had no jurisdiction to accept his guilty plea . Accordingly, Johnson claims,
his guilty pleas do not bar his argument that the Birchfield rule applies retroactively to his
collateral attack on his convictions. We agree with Johnson.
A district court has subject-matter jurisdiction to convict a defendant of all crimes
cognizable under the laws of the State of Minnesota. See Reed v. State, 793 N.W.2d 725,
731 (Minn. 2010) (citing United States v. Cotton , 535 U.S. 625, 630 –31 (2002)). But a
court is without jurisdiction to convict a defendant of conduct that is not criminal. See Ex
parte Siebold, 100 U.S. 371, 377 (1879) (“[I]f the laws [criminalizing particular conduct]
are unconstitutional and void, the Circuit Court acquired no juri sdiction of the causes. Its
authority to indict and try the petitioners arose solely upon these laws.”) . If “a statute is

8
unconstitutional, it is not a law and it is as inoperative as if it had never been enacted.”
Fedziuk v. Co mm’r of Pub . Safety, 696 N.W.2d 340, 349 (Minn. 2005). Because “[a]n
offence created by [an unconstitutional law] is not a crime[, a] conviction under it is not
merely erroneous, but is illegal and void, and cannot be a legal cause of imprisonment.”
Siebold, 100 U.S. at 376 –77. Accordingly, if a defendant attacks the constitutionality of
the statute underlying the defendant’s conviction, as opposed to police or prosecutorial
conduct, the defendant assert s a challenge to the court’s subject-matter jurisdiction. See
Giersdorf v. A & M Constr., Inc., 820 N.W.2d 16, 20 (Minn. 2012) (noting that subject -
matter jurisdiction refers to a court’s power to decide a particular case).
Johnson is in effect asserting a challenge to subject-matter jurisdiction. Johnson
argues that he was convicted under a statute that is unconstitutional as applied to him.
Johnson’s argument therefore attacks the subject-matter jurisdiction of the district court.
And, by pleading guilty, Johnson did not forfeit his righ t to make this jurisdictional
argument.3 See McCullough & Sons, Inc. v. City of Vadnais Heights , 883 N.W.2d 580,
585 (Minn. 2016) (citing Seehus v. Bor -Son Constr., Inc. , 783 N.W.2d 144, 147 (Minn.
2010)) (noting that subject-matter jurisdiction may not be waived by the parties).
In urging us to reach the opposite conclusion and find forfeiture, the State cites Hirt
v. State, 244 N.W.2d 162 (Minn. 1976) . There, we held that the “defendant waived his
right to raise the Fourth Amendment issues wh en he pleaded guilty.” Id. at 162. But

3 It is well -established that we have the authority, i.e. jurisdiction, to determine
whether we have jurisdiction. City of Duluth v. Fond du Lac Band of Lake Superior
Chippewa, 843 N.W.2d 577, 582 (Minn. 2014); see United States v. Ruiz , 536 U.S. 622,
628 (2002).

9
Johnson is not attacking the conduct of the police . He is not challenging a search as a
violation of the Fourth Amendment in either case. Indeed, no searches occurred. He is
also not arguing that he was compelled to consent to a chemical test under pain of
prosecution. Indeed, no chemical tests occurred. Nor does Johnson challenge the
reasonable suspicion underlying the stops or the probable cause that justified his arrests. If
he were asserting any of these Fourth Amendment claims in a postconviction petition, the
petition should be denied. Id.
Instead of making an argument that his Fourth Amendment rights were violated,
Johnson alleges that, because the Birchfield rule makes the Minnesota test-refusal statute
unconstitutional as applied to him, hi s convictions for violating that statute are invalid.
That argument is fundamentally a subject-matter jurisdiction challenge. We therefore hold
that Johnson ’s guilty pleas did not forfeit his argumen t that the Birchfield rule applies
retroactively.
II.
We turn next to the parties’ dispute over the retroactivity of the Birchfield rule.
Whether a rule of federal constitutional law applies retroactively to convictions that were
final when the rule was announced is a legal question that we review de novo. Campos v.
State, 816 N.W.2d 480, 485 (Minn. 2012) .4 We apply the standard from Teague v. Lane,

4 The retroactivity analysis is done only if a conviction was final before the new rule
was announced. See Campos, 816 N.W.2d at 488. Because Johnson did not file a direct
appeal of either of his test-refusal convictions, the conviction became final when the time
for filing a direct appeal expire d. See Hutchinson v. State , 679 N.W.2d 160, 162 (Minn.
2004). Johnson had 90 days in which to file a direct appeal of his test-refusal convictions.

10
489 U.S. 288 (1989), to determine the retroactive effect of a rule of federal constitutional
law. See Danforth v. State, 761 N.W.2d 493, 498 (Minn. 2009).
Under Teague, we ask whether the rule in question is a new rule or an old rule. If
it is a new rule, then the rule is applied only to cases that are not yet final when the rule
was announced, and the rule generally has no retroactive effect. Teague, 489 U.S. at 305–
06. The parties agree that the Birchfield rule is a new rule for purposes of the Teague
retroactivity analysis, and we will assume it is a new rule in this appeal.
Although a new rule of law generally does not apply retroactively to final
convictions, Teague provides two exceptions. Teague, 489 U.S. at 311. A new rule may
be applied retroactively if it: (1) is substantive, as compared to procedural, or (2) is a new
“watershed” rule of criminal procedure. See Schriro v. Summerlin, 542 U.S. 348, 351–52
(2004); see also Danforth , 761 N.W.2d at 496. Only the first exception is at issue here ,
and the parties dispute whether the Birchfield rule is substantive or procedural.
The State argues that the Birchfield rule is procedural, controlling only police
conduct, redefining the scope of searches permissible under the Fourth Amendment, and
leaving no private conduct categorically beyond the scope of the test-refusal statute.
Johnson contends that Birchfield created a substantive rule because it changed the elements
of the crime of test refusal and narrowed the scope of the test -refusal statute, effectively
creating a class of people constitutionally immune from punishment.

See Minn. R. Crim. P. 28.02, subd. 4(3)(a). Johnson’s 2010 and 2015 convictions therefore
were both final when the Birchfield rule was announced in 2016. This conclusion is true
regardless of whether we use the date that Birchfield was decided, June 23, 2016, or the
date that Trahan and Thompson were decided, October 12, 2016.

11
To address the parties’ arguments and determine whether a rule is substantive or
procedural, we look to the nature of the rule. A rule is substantive if it “alters the range of
conduct or the class of persons that the law punishes.” Schriro, 542 U.S. at 353. In other
words, a decision that “narrow[s] the scope of a criminal statute,” as well as a constitutional
determination that “place [s] particular conduct or persons covered by the statute beyond
the State’s power to punish” is substantive for purposes of the retroactivity analysis. Id. at
351–52. Such rules apply retroactively because they “ ‘necessarily carry a significant risk
that a defendant stands convicted of an act that t he law does not make criminal.’ ” Id. at
352 (quoting Bousley v. United States, 523 U.S. 614, 620 (1998)).
A procedural rule, on the other hand, “regulate[s] only the manner of determining
the defendant’s culpability.” Id. at 353 (emphasis omitted). Such rules simply “alter ‘the
range of permiss ible methods for determining whether a defendant’s conduct is
punishable.’ ” Welch v. United States , 578 U.S. ___, 136 S. Ct. 1257, 1265 (2016)
(quoting Schriro, 542 U.S. at 353). Procedural rules are not applied retroactively because
they raise only “ the possibility that someone convicted with use of the invalidated
procedure might have been acquitted otherwise.” Schriro, 542 U.S. at 352 (emphasis
added).
The Birchfield rule does not merely regulate the manner in which a defendant is
determined to be guilty or not guilty. The rule instead changes who can be prosecuted for
test refusal. Prior to Birchfield, Minnesota statutes provided that persons could be
convicted of test refusal if they “refuse[d] to submit to a chemical test of the person’s blood,
breath, or urine.” See Minn. Stat. § 169A.20 (2016). But under the Birchfield rule, persons

12
may be convicted of test refusal only if they refuse to submit to a breath test or if they
refuse to submit to a blood or urine test when the police have a search warrant or a valid
exception to the warrant requirement applies. Because of the Birchfield rule, those drivers
who refuse to submit to warrantless blood or urine tests cannot be prosecuted unless the
State proves that an exception to the warrant requirement applies. If no exception is
proved, these drivers then are beyond the power of the State to punish.
In this way, the Birchfield rule operates similarly to the rule at issue in Bousley v.
United States , 523 U.S. 614 (1998), in which the Supreme Court determine d the
retroactivity of Bailey v. United States , 516 U.S. 137 (1995) . In Bailey, the Cour t
considered the “use” prong of a statute that imposed penalties for us ing or carrying a
firearm when committing a crime. Bailey, 516 U.S. at 138–39; see 18 U.S.C. § 924(c)(1)
(2012) (imposing 5-year sentence on any person who “during a ny crime of violence . . .
uses or carries a firearm”). The Court determined that the “use” of a firearm included only
the “active employment of the firearm” and not mere possession. Bailey, 516 U.S. at 144.
Subsequently, the Court in Bousley concluded that Bailey was substantive and
would apply to a post-Bailey collateral attack of a conviction based on a guilty plea because
the rule mandated that a “ criminal statute does not reach certain conduct.” Bousley,
523 U.S. at 620 ; see also Welch, 578 U.S. at ___, 136 S. Ct. at 1265 (holding that a rule
that “changed the substantive reach” of the Armed Career Criminal Act by altering “the
range of conduct or the class of persons” the act punished was substantive (citation omitted)

13
(internal quotation marks omitted) ). The same is true of Minnesota’s test -refusal statute
after Birchfield.5
The Birchfield rule has placed a category of conduct outside t he State’s power to
punish. Now, a suspected impaired driver may only be convicted of tes t refusal if that
person refused a breath test or refused a blood or urine test that was supported by a warrant
or a valid warrant exception. The Birchfield rule therefore is substantive.
In urging us to reach the contrary conclusion and hold that the Birchfield rule is
procedural, the State asserts that the rule merely modified police conduct. Specifically, the
State focuses on the fact that, after Birchfield, police must secure a warrant or demonstrate
that an exception to the warrant requirement applies before demanding a blood or urine
test. Because the rule changed the procedure the police must follow before a driver may
be prosecuted for test refusal, the State argues, the Birchfield rule must be procedural and
cannot be substantive. We disagree.
As the Supreme Court explained in Montgomery v. Louisiana , focusing on a
procedural aspect of a substantive rule “conflates a procedural requirement necessary to
implement a substantive guarantee with a rule that ‘regulates[s] only the manner of
determining the defendant’s culpability .’ ” 577 U.S. ___, 136 S. Ct. 718, 734 –35 (2016)
(emphasis omitted) (quoting Schriro, 542 U.S. at 353) . In other words, simply because a
rule touches on procedure does not mean that the rule is procedural for retroactivity

5 In fact, after the Birchfield rule was announced, the Legislature amended the test -
refusal statute to expressly reflect the changes required by the Birchfield rule. See Act of
May 23, 2017, ch. 83, art. 2, § 2, 2017 Minn. Laws 351, 355 (codified at Minn. Stat.
§ 169A.20, subd. 2 (Supp. 2017)).

14
purposes. And although the State is correct in noting that the Birchfield rule regulates the
conduct of police officers when performing chemical testing, the rule does not regulate the
manner of determining a defendant’s culpability when a person has refuse d a warrantless
blood or urine test and no warrant exception applies; it puts that conduct beyond the power
of a court to convict. In other words, for anyone convicted of test refusal for refusing a
blood or urine test when the police did not have a warrant or a warrant exception did not
apply, no procedure, “ ‘even the use of impeccable fact finding procedures’ ” could now
validate a conviction for test refusal because that crime no longer exi sts. See Welch,
578 U.S. at ___, 136 S. Ct. at 1265 (quoting United States v. U.S. Coin & Currency ,
401 U.S. 715, 724 (1971)) .6 Because the function of the Birchfield rule is substantive ,
defining who can and who cannot be culpable for refusing to submit to a chemical test, the
fact that the police need to chan ge their procedure to conform to the rule does not change
the nature of the rule for retroactivity purposes. See id. at ___, 136 S. Ct. at 1266
(explaining that the determinative factor is “whether the new rule itself has a procedural
function or a substantive function —that is, whether it alters only the procedures used to

6 The State argues that Welch is distinguishable. In Welch, the Court addressed the
retroactivity of the rule from Johnson v. United States , 576 U.S. ___, 135 S. Ct. 2551
(2015), a case where the Court struck down part of a federal sentencing statute. We agree
with the State that the Birchfield rule does not result in any part of the test -refusal statute
being facially unconstitutional. But that does not mean that the Birchfield rule is n ot
substantive. The Court in Welch considered and rejected the idea that there is a difference
for retroactivity purposes between a new rule that invalidates a statute and one that does
not. See Welch, 578 U.S. at ___, 136 S. Ct. at 1267 (explaining that even if a rule simply
interpreted a statute, it would still be analyzed under the “normal crit eria for a substantive
rule”). The invalidation of the statute in Welch, then, has no bearing on whether the
Birchfield rule is substantive.

15
obtain the conviction, or alters instead the range of conduct or class of persons that the law
punishes”).
Finally, the State argues that, for a rule to be retroactive, it must apply to all cases.
Because an individual, case-by-case analysis would be required to apply the Birchfield rule,
the State contends, the rule is not retroactive. The State is correct that the application of
the Birchfield rule may require each case to be assessed individually to determine whether
a warrant or an exception to the warrant requirement existed at the time of the test refusal.
But, as Johnson argues, Montgomery, 577 U.S. ___, 136 S. Ct. 718, shows that even a rule
requiring a case-by-case analysis can be retroactive.7
In Montgomery, the Court examined the retroactivity of its decision in Miller v.
Alabama, 567 U.S. 460 (2010) (concluding that mandatory life sentences without parole
for juveniles violated the Eighth Amendment ). Miller “did not bar a punishment for all
juvenile offenders,” because it allowed courts, following a hearing, to impose a sentence
of life without parole on those juvenile offenders “whose crimes reflect permanent
incorrigibility.” Montgomery, 577 U.S. at ___, 136 S. Ct. at 734. And the Court expressly
recognized that a case-by-case analysis of each defendant was required to determine if they
could continue to be incarcerated without the possibility of parole. See id. at ___, 136 S. Ct.

7 The State also argues that Birchfield would be difficult to apply on a case -by-case
basis because it would require individual, procedurally distinct, postconviction
proceedings that may, as in this case, require examining an undeveloped record because of
guilty pleas. Concerns regarding application of the rule , however, cannot outweigh the
demands of justice. If a rule has been determined to be substantive, it must be applied
retroactively to all affected. See Teague , 489 U.S. at 300 (explaining that evenhanded
justice requires that the rule be applied retroactively to all who are similarly situated).

16
at 736 (“A State may remedy a Miller violation by permitting juvenile homicide offenders
to be considered for parole, rather than by resentencing them.”). The Court, however, still
concluded that Miller was substantive because it “raise[d] a grave risk that many are being
held in violation of the Constitution.” Id. at ___, 136 S. Ct. at 736.
Similarly here, there will need to be case-by-case determinations to assess whether
there was a warrant or an exception to the warrant requirement sufficient to sustain test -
refusal conviction s under the Birchfield rule. But t his case -by-case analysis does not
“transform [a] substantive rule[] into a procedural one[].” Id. at ___, 136 S. Ct. at 735.
For the reasons explained above, we hold that the Birchfield rule is substantive and
applies retroactively to Johnson’s convictions on collateral review. Even though the
Birchfield rule applies to Johnson’s convictions, reversal of those convictions is not
automatic. On remand, the district courts will need to apply the Birchfield rule and
determine if the test-refusal statute was unconstitutional as applied to Johnson.8
CONCLUSION
For the foregoing reasons, we reverse and remand to the district court for further
proceedings consistent with this opinion.
Reversed and remanded.

8 Under the Birchfield rule, the State cannot criminalize a driver’s refusal of a blood
or urine test absent a warrant or a showing of a valid exception to the warrant requirement.
One exception to the warrant requirement for blood and urine tests that could apply is
exigent circumstances. See Trahan , 886 N.W.2d at 222 . We express no opinion on
whether Missouri v. McNeely, 569 U.S. 141 (2013), applies to any exigent -circumstances
determination for either of Johnson’s test-refusal convictions.