Pursuant to Indiana Appellate Rule 65(E), the trial court and parties shall not take any action in reliance upon this opinion until it is certified.
Indiana Supreme Court Supreme Court Case No. 26S-CR-405 Parnell D. Lanier,
Appellant
-v-
State of Indiana,
Appellee
Argued: May 14, 2026 | Decided: November 10, 2026 Interlocutory Appeal from the Marion Superior Court No. 49D07-2405-F5-12646
The Honorable Joel A. Schneider, Magistrate On Petition to Transfer from the Indiana Court of Appeals No. 25A-CR-769
Opinion by Chief Justice Rush
Justices Massa, Goff, and Molter concur. Justice Slaughter dissents, believing that transfer should be denied and the Court of Appeals' opinion reinstated.
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Rush, Chief Justice.
Hoosiers are entitled to travel Indiana's roads free from arbitrary police interference. To that end, the Fourth Amendment to the United States Constitution and Article 1, Section 11 of the Indiana Constitution protect against unreasonable police searches or seizures, including traffic stops. Today we consider whether those protections permit a traffic stop for conduct the law does not prohibit. Under the Fourth Amendment, a police officer's objectively reasonable mistake of law can justify a stop. But when that law permits only one reasonable interpretation, an officer's contrary reading cannot alone justify a stop. We have not decided whether Article 1, Section 11 likewise permits a stop based on a reasonable mistake of law. Here, a police officer stopped a motorist for turning right out of a gas station parking lot without signaling. That stop led to the discovery of drugs and a handgun. In the ensuing criminal proceedings, the motorist moved to suppress the evidence under both constitutional provisions, arguing that he had violated no traffic statute. The State responded that he had violated a statute and that, even if not, the statute could reasonably be interpreted to require signaling in the circumstances. The trial court agreed with the State and denied the motion to suppress. We reverse and remand. We first hold that the statute the State relies on is unambiguous as applied to this turn and did not require the motorist to signal. We then hold that the officer's contrary interpretation was not objectively reasonable, and thus the traffic stop violated the motorist's Fourth Amendment rights. Because the State has not raised any exception to the exclusionary rule, the evidence must be suppressed. That remedy affords complete relief, so we leave the state constitutional question for a future case.
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Facts and Procedural History
In May 2024, Parnell Lanier turned right from a gas station's parking- lot exit onto a city street without signaling. Officer Collin Poynter,1who was parked across the street, followed Lanier and initiated a traffic stop. When the officer approached the vehicle, he smelled marijuana and saw a holstered handgun in Lanier's lap. The ensuing investigation uncovered marijuana and a digital scale in the vehicle and, during booking, suspected cocaine in one of Lanier's socks.
The State ultimately charged Lanier with Level 5 felony unlawful carrying of a handgun, Level 5 felony possession of cocaine, and Class A misdemeanor possession of marijuana. Before trial, Lanier moved to suppress the drugs and handgun, asserting that the stop violated his federal and state constitutional rights because no law required him to use a turn signal and thus the stop "was not based upon a traffic violation."
At the hearing on Lanier's motion, Officer Poynter testified that he stopped Lanier for failing to signal. Later, when Lanier's attorney asked the officer to identify the governing law, he described a statute that had been "recently updated to remove the distance barrier" but still required a driver "to signal" before or during the movement. Lanier's attorney then directed the officer to Indiana Code section 9-21-8-24, a statute that in relevant part requires a motorist to use a turn signal when turning "a vehicle from a direct course upon a highway" or when changing "from one (1) traffic lane to another." The officer confirmed that this was the statute he relied on in conducting the traffic stop and identified the subsection governing turns from a direct course upon a highway as the applicable provision.
The hearing also addressed where Lanier began his turn. Lanier's attorney showed the officer Section 9-21-8-34, a statute that requires a motorist to yield when entering "a highway from a private road or
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driveway" but does not require signaling. And the officer agreed that Lanier began the turn from a private parking-lot exit, not from a highway. After the hearing, the trial court entered an order denying Lanier's motion. The court found the "facts and rationale" of Datzek v. State, 838 N.E.2d 1149 (Ind. Ct. App. 2005), trans. denied, "directly on point."
Although Datzek relied on former Section 9-21-8-25, which was repealed before the stop, the court concluded that Datzek's facts and rationale remained applicable and that Officer Poynter had not misinterpreted Sections 9-21-8-24 and -34. After the court denied Lanier's motion to reconsider, it certified the suppression order for interlocutory appeal, and the Court of Appeals accepted jurisdiction.
The Court of Appeals affirmed in a published opinion. Lanier v. State,
271 N.E.3d 1185 (Ind. Ct. App. 2025). Without deciding whether Section 9- 21-8-24 required Lanier to use a turn signal, the panel held that Officer Poynter's interpretation of the statute was objectively reasonable and that the stop therefore complied with the Fourth Amendment. Id. at 1192-93. The panel then adopted the same reasonable-mistake-of-law approach under Article 1, Section 11 and upheld the stop under that provision. Id. at 1193-94.
Lanier petitioned for transfer, which we now grant, vacating the Court of Appeals' opinion. Ind. Appellate Rule 58(A).
Standard of Review
When reviewing the denial of a motion to suppress, we defer to the trial court's factual findings unless clearly erroneous, viewing conflicting evidence in favor of the ruling while also considering substantial, uncontested evidence favorable to the defendant. Marshall v. State, 117 N.E.3d 1254, 1258 (Ind. 2019). But we review de novo both statutory interpretation and the constitutional validity of a traffic stop. Id.; Gary v. State, 276 N.E.3d 639, 642 (Ind. 2026).
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Discussion and Decision
When a police officer stops a vehicle for a suspected traffic infraction, the officer seizes the vehicle's occupants. Marshall v. State, 117 N.E.3d 1254, 1258 (Ind. 2019). Indiana motorists and passengers therefore enjoy two independent constitutional protections against unreasonable traffic stops. Id. The Fourth Amendment guarantees the "right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures." U.S. Const. amend. IV. And though Article 1, Section 11 of the Indiana Constitution uses substantially similar language, we conduct "a separate, independent analysis," which sometimes results in "broader protections." Marshall, 117 N.E.3d at 1258. Under the Fourth Amendment, a police officer may conduct a traffic stop based on reasonable suspicion, which exists when the officer can
"articulate some facts that provide a particularized and objective basis for believing a traffic violation occurred." Id. at 1259. But under Article 1, Section 11, the State must show that the officer's conduct was reasonable under the totality of the circumstances. Id. at 1262. For either constitutional provision, an objectively reasonable mistake about the facts can support a traffic stop. Heien v. North Carolina, 574 U.S. 54, 60-61 (2014); Mercado v. State, 200 N.E.3d 463, 471-72 (Ind. Ct. App. 2022), trans. denied. But an officer's mistaken belief that the law prohibits the observed conduct presents a different question.
The U.S. Supreme Court has held that an objectively reasonable mistake about the scope of an ambiguous statute can support a traffic stop under the Fourth Amendment. Heien, 574 U.S. at 66-68. We have not, however, resolved that issue under Article 1, Section 11. See State v. Keck, 4 N.E.3d 1180, 1184, 1186 (Ind. 2014) (addressing a mistake of law under the Fourth Amendment before Heien and declining to reach the state constitutional claim).
Here, the parties dispute whether Section 9-21-8-24 required Lanier to use a turn signal and, if it did not, whether a reasonable mistake of law justified the stop. We first explain why the statute does not require a signal for a right turn from a private commercial parking lot onto a city
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street. We then explain why the State's contrary reading is not objectively reasonable under Heien. And because we hold that the traffic stop violated the Fourth Amendment and that the resulting evidence must be suppressed, we need not decide Lanier's state constitutional claim.2
I. Section 9-21-8-24 did not require Lanier to use a turn signal.
Section 9-21-8-24 requires a driver to signal before making specified movements. Subsection (a) identifies those movements, and subsection (b)(2) requires "an appropriate stop or turn signal" before making them. Ind. Code § 9-21-8-24(a), (b)(2). Two movements are implicated here:
"turn[ing] a vehicle from a direct course upon a highway" (the "Direct Course Provision") and "chang[ing] from one (1) traffic lane to another"
(the "Traffic Lane Provision"). I.C. § 9-21-8-24(a)(2)-(3). The State contends that Lanier's turn fell within both provisions. Lanier counters that neither applied. We must therefore determine whether Lanier's turn was one of these movements.
When interpreting a statute, we start by reading its text in context and as part of a broader statutory scheme. Town of Linden v. Birge, 204 N.E.3d 229, 237 (Ind. 2023). If that analysis yields just one reasonable meaning, our inquiry ends. Fix v. State, 186 N.E.3d 1134, 1139 (Ind. 2022). Here, the disputed provisions are unambiguous as applied to Lanier's turn. The Direct Course Provision requires a motorist to signal before turning from a course when already upon a highway, and the Traffic Lane Provision requires a motorist to signal before changing from one traffic lane to another. Neither requires a motorist to signal when turning right out of a private commercial parking lot onto a city street. And related statutes confirm that plain meaning.
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Article 9-21 generally regulates vehicle operation on Indiana's highways and residential-subdivision roads, not private commercial property. It "applies throughout Indiana." I.C. § 9-21-1-1. And "[e]xcept when a different place is specifically referred to," it applies only "to the operation of vehicles upon highways and private roads of a residential subdivision, regardless of who maintains them." I.C. § 9-21-1-9. Notably, the private commercial parking lot at issue here is neither. A city street, by contrast, falls within the statutory definition of a
"highway." That term "means the entire width between the boundary lines of every publicly maintained way when any part of the way is open to the use of the public for purposes of vehicular travel," including "an alley in a city or town." I.C. §§ 9-13-1-1, 9-13-2-73. So Lanier's entry onto the city street brought him within Article 9-21's general reach. But that does not establish that his turn was a movement for which Section 9-21-8- 24 required a signal. We must still examine the language describing each movement.
We start with the Direct Course Provision, which requires a course on the highway from which the vehicle turns. I.C. § 9-21-8-24(a)(2). As Lanier asserts, this provision refers to vehicles already traveling on a highway when they turn. But the State believes it also covers vehicles that "enter the highway" from private lots because the vehicle starts off
"perpendicular to the lanes of travel" and then changes its "direct course upon the highway into a lane of travel." We disagree. When statutory words and phrases are undefined, the General Assembly has instructed us to construe them "in their plain, or ordinary and usual, sense." I.C. § 1-1-4-1(1). And we often consult dictionaries to identify that meaning. See, e.g., Nardi v. King, 253 N.E.3d 1098, 1104 (Ind. 2025). Here, the undefined words used in the Direct Course Provision describe an existing path on the highway. Grammatically, the phrase
"upon a highway" modifies "a direct course." In the context of highway travel, a "course" is a "path over which something moves," Course, Merriam-Webster's Dictionary, https://www.merriam- webster.com/dictionary/course (last visited Nov. 10, 2026), while "direct"
means "proceeding from one point to another in . . . space without
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deviation or interruption," Direct, Merriam-Webster's Dictionary, https://www.merriam-webster.com/dictionary/direct (last visited Nov. 10, 2026). And, as used here, "upon" is merely a synonym for "on." Upon, Merriam-Webster's Dictionary, https://www.merriam- webster.com/dictionary/upon (last visited Nov. 10, 2026).3So a "direct course upon a highway" is a vehicle's existing path along that highway. See, e.g., Ruby v. Easton, 207 N.W.2d 10, 15, 17 (Iowa 1973) (construing
"direct course upon a highway" to mean movement along a straight or curved highway).
By contrast, a vehicle turning from a private commercial parking lot onto a highway is not turning "from a direct course upon a highway."
Although such a vehicle completes its turn on the highway, it does not turn from a path along the highway. The State's contrary reading accounts for where the turn ends but not the course from which it begins. And in ordinary English, a vehicle entering a highway turns "onto" it, rather than
"upon" it. State v. Brown, 81 P.3d 916, 917 (Wash. Ct. App. 2003). Related statutes further confirm the difference between entering a highway and traveling along it. For example, under Section 9-21-8-34, "[a] person who drives a vehicle that is about to enter or cross a highway from a private road or driveway shall yield the right-of-way to all vehicles approaching on the highway." I.C. § 9-21-8-34. "Private road" and
"driveway" are defined terms meaning "a way or place in private ownership that is used for vehicular travel by the owner and those having express or implied permission from the owner but not by other persons."
I.C. § 9-13-2-49. Another statute regulates vehicles "emerging from an alley, a driveway, or a building" in "a business or residence district,"
requiring the vehicle to stop "before driving onto a sidewalk or into the sidewalk area extending across an alleyway or a private driveway." I.C. §
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9-21-8-42. Finally, a third statute requires a farm-wagon operator crossing a state highway from one field to another to stop the wagon before proceeding. I.C. § 9-21-8-45(b).
By expressly addressing approaches from private roads, driveways, buildings, and fields, these provisions illustrate Article 9-21's exception for a specifically identified "different place." I.C. § 9-21-1-9. Their duties can coexist with a signaling requirement, so their silence about signaling is not alone dispositive. The relevant contrast is how they describe the regulated movement: entering or crossing a highway or sidewalk. And the Direct Course Provision instead addresses only a turn "from a direct course upon a highway." I.C. § 9-21-8-24(a)(2).
The Traffic Lane Provision likewise requires a starting point that Lanier's turn lacked: a traffic lane. See I.C. § 9-21-8-24(a)(3). The State contends that the undefined term "traffic lane" could include the entry and exit lanes of a busy gas station. But a motorist entering a highway from a parking lot does not, in ordinary English, "change from one . . . traffic lane to another" or, more colloquially, "change lanes." Id. Statutory context confirms the distinction. The term "traffic" is a defined term including "vehicles" that are "using any highway for purposes of travel." I.C. § 9-13-2-182. Chapter 8 likewise uses "lanes for traffic" to describe divisions of a roadway, which Title 9 defines as the
"part of a highway improved, designed, or ordinarily used for vehicular travel." I.C. §§ 9-21-8-11.5, 9-13-2-157(a). Read with Article 9-21's scope provision, these definitions exclude a private commercial parking-lot exit from the term "traffic lane," regardless of how many vehicles use it. A driver entering a highway from such an exit therefore does not change from one traffic lane to another.
Datzek v. State, 838 N.E.2d 1149 (Ind. Ct. App. 2005), trans. denied, which the trial court relied on, does not alter our analysis. There, the Court of Appeals upheld a stop under former Section 9-21-8-25, which required a driver to use a continuous turn signal for at least 200 feet before turning or changing lanes. Id. at 1154-56. Although the court addressed arguments under Sections 9-21-8-24 and -34, it found a violation of Section 9-21-8-25 and did not analyze Article 9-21's geographic scope. Id. at 1155-56.
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The General Assembly also repealed Section 9-21-8-25 without expanding the movements covered by Section 9-21-8-24. Pub. L. No. 118- 2022, §§ 22-23, 2022 Ind. Acts 1329, 1350-51. The same enactment amended Section 9-21-8-24(b) to require a signal before a covered movement regardless of whether another vehicle might be affected, but it left the movements listed in subsection (a) unchanged. Id. Thus, whether Lanier had to signal depends on whether his turn fell within those provisions, not the repealed statute applied in Datzek. In sum, Lanier's turn fell within neither disputed provision. The undisputed evidence establishes that he began the right turn from a gas station parking-lot exit, not from a highway. He therefore did not turn from a direct course upon a highway or change from one traffic lane to another. So Section 9-21-8-24 did not require him to signal. But that conclusion does not alone resolve whether the stop was constitutional. We address that issue next.
II. Heien does not save the stop because the statute is unambiguous as applied here.
The State contends that one could reasonably interpret Section 9-21-8- 24 as applying to Lanier's turn, even if that interpretation is wrong. It therefore asks us to uphold the stop under Heien v. North Carolina, 574 U.S. 54 (2014), and to adopt the same reasonable-mistake-of-law approach under Article 1, Section 11. We begin with the federal claim. Under Heien, the question is whether the statute reasonably supported the officer's mistaken reading. It did not.
In Heien, an officer stopped a vehicle because one of its two brake lights did not work. 574 U.S. at 57. That stop led to the discovery of cocaine, and the defendant moved to suppress it. Id. at 57-58. Although the North Carolina Court of Appeals had held that state law required only one working brake light, the North Carolina Supreme Court upheld the stop after finding the officer's mistake was reasonable. Id. at 58-59. The U.S. Supreme Court agreed, reasoning that "reasonable men make mistakes of law" as well as mistakes of fact and that "such mistakes are no less
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compatible with the concept of reasonable suspicion." Id. at 61. The Court also recognized that officers may need to decide in the field how an unclear statute applies. Id. at 66. But the error must be objectively reasonable. Id. That standard, the Court explained, is more demanding than the one used for qualified immunity, and an officer cannot benefit from a "sloppy study of the laws." Id. at 67.
The statutory text at issue in Heien supported the officer's reading. Although the statute referred to "a stop lamp," it also referred to "other rear lamps," language suggesting "to the everyday reader of English" that a stop lamp was a type of rear lamp. Id. at 67-68. And because the statute required all originally equipped rear lamps to remain in working order, the Court held that it could reasonably be read to require all brake lights to function. Id. at 68. That reading was further reinforced by every member of the North Carolina Supreme Court finding the officer's understanding reasonable and the absence of prior appellate construction of the statute. Id. The Court therefore held that the officer's mistake of law was objectively reasonable and supplied reasonable suspicion. Id. Justice Kagan, joined by Justice Ginsburg, concurred in full but wrote separately to clarify the standard. She explained, "If the statute is genuinely ambiguous, such that overturning the officer's judgment requires hard interpretive work, then the officer has made a reasonable mistake." Id. at 70 (Kagan, J., concurring). Indeed, "the statute must pose a 'really difficult' or 'very hard question of statutory interpretation,'" and such cases should be "exceedingly rare." Id. (citation modified). Since then, multiple federal courts of appeals have applied these important limitations. See, e.g., United States v. Diaz, 854 F.3d 197, 203-04 (2d Cir. 2017); Scott v. City of Albuquerque, 711 F. App'x 871, 877 & n.6 (10th Cir. 2017). We too find this formulation persuasive because it directs the inquiry to the statutory uncertainty that justified the stop in Heien, not simply to whether an officer made an understandable error. The proper construction of Section 9-21-8-24 does not require such
"hard interpretive work." As explained above, the Direct Course Provision addresses a vehicle turning from a course already upon a highway. Reading "upon" in isolation to include movement "onto" a
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highway does not account for the full phrase, "from a direct course upon a highway." Other dictionary meanings do not make a statutory phrase ambiguous when context resolves its meaning. See Deal v. United States,
508 U.S. 129, 131-32 (1993). And the Traffic Lane Provision requires a vehicle to move from one traffic lane to another. Entering a highway from a private commercial parking lot is not such a lane change. And that ordinary meaning is confirmed by the definitions of "traffic" and
"roadway," read within Article 9-21's scope. The State nevertheless emphasizes two circumstances. Officer Poynter had to apply the statute in the field without a prior appellate decision applying the provisions to such a turn, and the Court of Appeals later concluded that his interpretation was reasonable. We recognize the difficulty officers face in applying unclear law, but neither circumstance substitutes for statutory language that reasonably supports the officer's reading. In Heien, for example, the Court first identified statutory language supporting the officer's reading and then noted the state supreme court's agreement and the absence of prior appellate construction. 574 U.S. at 67-68; accord United States v. McCullough, 851 F.3d 1194, 1201 (11th Cir. 2017) ("[T]he presence or absence of an appellate decision is not dispositive of whether an officer's interpretation is objectively reasonable."). Those circumstances therefore reinforced a reading the text already supported.
No comparable textual support exists here. The two provisions invoked by the State unambiguously require a signal only when a motorist turns from a direct course upon a highway or changes from one traffic lane to another. Lanier did neither. He turned right from a gas station parking lot onto a city street. Officer Poynter's contrary interpretation was therefore not objectively reasonable. See Heien, 574 U.S. at 66; United States v. Stanbridge, 813 F.3d 1032, 1037 (7th Cir. 2016). And because that interpretation supplied the only asserted basis for reasonable suspicion, the traffic stop violated Lanier's Fourth Amendment rights. The exclusionary rule generally bars evidence obtained through a Fourth Amendment violation. Shotts v. State, 925 N.E.2d 719, 723 (Ind. 2010). Because the State has not raised any exception to that rule, the
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evidence resulting from the stop must be suppressed. That remedy affords Lanier complete relief, so we need not decide whether Article 1, Section 11 permits a traffic stop based on a reasonable mistake of law. See Keck, 4 N.E.3d at 1186. We leave that question for a future case.
Conclusion
For these reasons, we reverse the trial court's order denying Lanier's motion to suppress and remand with instructions to grant the motion and conduct further proceedings consistent with this opinion. Massa, Goff, and Molter, JJ., concur.
Slaughter, J., dissents, believing that transfer should be denied and the Court of Appeals' opinion reinstated.
A T T O R N E Y S F O R A P P E L L A N T
Timothy J. Burns
Abigail H. Kim
Indianapolis, Indiana
Theodore E. Rokita
Attorney General of Indiana Tyler G. Banks
Section Chief, Capital & Habeas Litigation Caroline G. Templeton
Assistant Section Chief, Criminal Appeals Michelle Hawk Kazmierczak
Deputy Attorney General
Indianapolis, Indiana
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