IN THE COURT OF CRIMINAL APPEALS

OF TEXAS

NO. PD-0799-19

THE STATE OF TEXAS, Appellant

v.

SHEILA JO HARDIN, Appellee

ON STATE’S PETITION FOR DISCRETIONARY REVIEW

FROM THE THIRTEENTH COURT OF APPEALS

NUECES COUNTY

SLAUGHTER, J., filed a concurring opinion. 

CONCURRING OPINION

I agree with the Court’s statutory interpretation of Texas Transportation Code 

Section 545.060(a) and its ultimate conclusion upholding the trial court’s ruling granting 

Appellee’s motion to suppress. But, I write separately to observe that this situation appears 

to be a classic case of reasonable mistake of law by the officer who pulled Appellee over. 

See Heien v. North Carolina, 574 U.S. 54 (2014) (holding that officer’s reasonable but 

mistaken understanding of traffic law could nevertheless give rise to reasonable suspicion 
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to justify traffic stop). Here, the officer’s mistaken interpretation of the law was entirely 

reasonable in view of the nuanced statutory language and the conflicting caselaw from this 

Court and the intermediate courts of appeals interpreting it. Thus, had the State raised the 

mistake-of-law issue in the trial court, it appears that the court would have erred by granting 

Appellee’s motion over that argument. Nevertheless, the record reflects that the State did 

not raise any such argument in the trial court, instead urging only that the officer’s 

understanding of Transportation Code Section 545.060(a) was in fact correct. Because the 

State did not raise any alternative argument based on mistake of law, this Court cannot now 

reverse the trial court’s ruling on a basis not presented to it. See State v. Mercado, 972 

S.W.2d 75, 77 (Tex. Crim. App. 1998). Therefore, being presented with no basis to reverse, 

I join the Court’s opinion and write separately only to note that the State could have 

successfully raised mistake of law.

I. Heien v. North Carolina and Reasonable Mistakes of Law

The Fourth Amendment protects against unreasonable searches and seizures. U.S.

CONST. AMEND. IV. Warrantless traffic stops are a form of seizure and are permissible if 

supported by reasonable suspicion. Derichsweiler v. State, 348 S.W.3d 906, 914 (Tex. 

Crim. App. 2011). Reasonable suspicion is a totality-of-the-circumstances determination 

and is found to exist when the officer has specific, articulable facts that, when combined 

with rational inferences, would lead the officer to reasonably believe that an offense has 

been, or is about to be, committed. Ford v. State, 158 S.W.3d 488, 492–93 (Tex. Crim. 

App. 2005). 
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In Heien v. North Carolina, the Supreme Court for the first time expressly 

recognized that an officer’s reasonable mistake of law (and not just a reasonable mistake 

of fact) may give rise to reasonable suspicion justifying a temporary investigative 

detention. 574 U.S. at 57. In Heien, an officer stopped a vehicle because one of its two 

brake lights was out, but a court later determined that a single working brake light was all 

that the law required. Id.

1 The Supreme Court ultimately held that the officer’s mistake 

about the meaning of the brake-light law was reasonable, such that the stop was lawful 

under the Fourth Amendment. Id. In explaining its reasoning, the Court first observed that 

the “ultimate touchstone of the Fourth Amendment is reasonableness.” Id. at 60. It 

continued, “To be reasonable is not to be perfect, and so the Fourth Amendment allows for 

some mistakes on the part of government officials, giving them ‘fair leeway for enforcing 

the law in the community’s protection.’” Id. at 60–61 (quoting Brinegar v. United States, 

338 U.S. 160, 176 (1949)). Recognizing that the Court had already held that searches and 

seizures based on mistakes of fact can be reasonable, it further observed that the limiting 

principle of that rule is that such “mistakes must be those of reasonable men.” Id. at 61 

(quoting Brinegar, 338 U.S. at 176). The Court then extended this principle to situations 

involving reasonable mistakes of law, stating:

But reasonable men make mistakes of law, too, and such mistakes are no less 

compatible with the concept of reasonable suspicion. Reasonable suspicion 

arises from the combination of an officer’s understanding of the facts and his 

1 The law at issue in Heien provided that a car must be “equipped with a stop lamp on the rear of 

the vehicle. The stop lamp shall display a red or amber light visible from a distance of not less than 

100 feet to the rear in normal sunlight, and shall be actuated upon application of the service (foot) 

brake. The stop lamp may be incorporated into a unit with one or more other rear lamps.” N.C. 

Gen. Stat. Ann. § 20–129(g) (2007).
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understanding of the relevant law. The officer may be reasonably mistaken 

on either ground. Whether the facts turn out to be not what was thought, or 

the law turns out to be not what was thought, the result is the same: The facts 

are outside the scope of the law. There is no reason, under the text of the 

Fourth Amendment or our precedents, why this same result should be 

acceptable when reached by way of a reasonable mistake of fact, but not 

when reached by way of a similarly reasonable mistake of law.

Id. Applying these principles to Heien’s case, the Court had “little difficulty concluding 

that the officer’s error of law was reasonable” under those circumstances. Id. at 67. It 

examined the pertinent statutory language and observed that the statute was not entirely 

clear with respect to whether one or two brake lights was required. Id. at 68. “It was thus 

objectively reasonable for an officer in Sergeant Darisse’s position to think that Heien’s 

faulty right brake light was a violation of North Carolina law. And because the mistake of 

law was reasonable, there was reasonable suspicion justifying the stop.” Id.2

II. The officer’s mistaken understanding of Transportation Code Section 

545.060(a) was reasonable.

Applying the Supreme Court’s reasoning in Heien to the situation at hand, the 

officer’s mistaken understanding of Transportation Code Section 545.060(a) was entirely 

reasonable for Fourth Amendment purposes. The statute provides, in relevant part, that:

(a) An operator on a roadway divided into two or more clearly marked 

lanes for traffic

2 I recognize that, unlike the present situation, the Supreme Court also considered that the provision 

at issue had “never been previously construed by North Carolina’s appellate courts.” Heien, 574 

U.S. at 68. But the Court did not suggest that this was a condition precedent to applicability of the 

mistake-of-law doctrine. Instead, this was but one factor taken into account in examining the 

overall reasonableness of the officer’s mistake. Further, as discussed in the next section, though 

the statute at issue here had been construed by several appellate courts, those interpretations were 

not all in agreement. Thus, before today’s holding, the caselaw has been in a state of conflict on 

the meaning of this statutory language. 
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(1) shall drive as nearly as practical entirely within a single lane; 

and

(2) may not move from the lane unless that movement can be made 

safely.

TEX. TRANSP.CODE § 545.060(a). The Court’s opinion concludes that this language means 

that a driver may lawfully briefly leave her lane of traffic, so long as doing so is not unsafe. 

But, as shown by the competing dissenting opinions in this case, reasonable minds can 

disagree on the meaning of the statutory terms. See generally, dissenting opinions of Keller, 

P.J., and Yeary, J. Thus, it is not implausible or unreasonable to argue that failing to “drive 

as nearly as practical entirely within a single lane” constitutes a violation of the statute, 

regardless of whether such action is in any way unsafe. Indeed, in this Court’s plurality 

opinion in Leming v. State, four judges agreed with that view of the statutory language. 493 

S.W.3d 552, 559–60 (Tex. Crim. App. 2016) (plurality op.).

3 Yet, prior to Leming, several 

intermediate appellate courts had reached the opposite conclusion and interpreted the 

statute in the manner adopted by this Court’s opinion today.4 Thus, the existence of these 

competing interpretations of the statutory language demonstrates that even a well-informed 

officer acting at the time of Appellee’s traffic stop could have been reasonably mistaken as

to whether her conduct constituted a violation of the law.

3 Four judges, however, disagreed, joining two dissenting opinions. See Leming, 493 S.W.3d at 

566 (Keasler, J., dissenting); id. at 573 (Newell, J., dissenting).

4 See State v. Houghton, 384 S.W.3d 441 (Tex. App.—Fort Worth 2012, no pet.) (holding Section

545.060(a) to only be violated when a person drifted out of his or her lane in an unsafe manner); 

State v. Cerny, 28 S.W.3d 796 (Tex. App.—Corpus Christi-Edinburg 2000, no pet.) (same); State 

v. Arriaga, 5 S.W.3d 804 (Tex. App.—San Antonio 1999, pet. ref’d) (same); Hernandez v. State, 

983 S.W.2d 867 (Tex. App.—Austin 1998, pet. ref’d) (same).
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While this Court has not previously had the opportunity to consider whether an 

officer’s mistaken interpretation of Transportation Code Section 545.060(a) may constitute 

a reasonable mistake of law satisfying Fourth Amendment concerns, the United States Fifth 

Circuit Court of Appeals has recently considered such a case and held that no Fourth 

Amendment violation occurred. See United States v. Valenzuela-Godinez, 816 Fed. App’x 

914 (5th Cir. 2020) (per curiam). In that case, a police officer followed a driver for several 

miles and observed his vehicle “veer over the fog line several times.” Id. at 915. The officer 

initiated a traffic stop based on his understanding of Section 545.060(a). Id. at 916. During 

the stop, officers discovered cocaine underneath the back seat. Id. In upholding the denial 

of the motion to suppress based on the officer’s reasonable misunderstanding of the law, 

the Fifth Circuit noted that the disagreement between Texas appellate courts and the 

plurality opinion in Leming supported a conclusion that the officer’s understanding, while 

mistaken, was reasonable. Id. at 918 (“In light of the statute’s ambiguous text, coupled with 

the clear divide among Texas courts over its meaning, we hold that [the officer’s] belief 

that Valenzuela-Godinez broke the law by failing to maintain a single lane of traffic, even 

if mistaken, was objectively reasonable.”). Other Fifth Circuit decisions have also endorsed 

the applicability of mistake of law under similar scenarios involving Section 545.060(a).

See United States v. Cedillo, 855 Fed. App’x 954 (5th Cir. 2021) (per curiam); United 

States v. Neal, 777 Fed. App’x 776, 776–77 (5th Cir. 2019) (per curiam) (“[A]ny belief by 

officers that [Section] 545.060(a) required only failure to maintain a lane (and not, in 

addition, unsafe movement), even if mistaken, was objectively reasonable.”). 
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III. The State failed to raise mistake of law in the trial court, such that it 

cannot now rely on that theory to support reversal of the trial court’s 

ruling.

Notwithstanding the foregoing analysis, the State did not raise the issue of mistake 

of law in the trial court. Therefore, this Court may not now rely on that theory as a basis 

for reversing the trial court’s suppression ruling here. That is because a reviewing court 

generally cannot reverse a trial court’s ruling on grounds not presented to the trial court 

when reviewing a decision on a motion to suppress. See Mercado, 972 S.W.2d at 75; see 

also Martinez v. State, 91 S.W.3d 331, 336 (Tex. Crim. App. 2002) (noting that “appellate 

courts may uphold a trial court’s ruling on any legal theory or basis applicable to the case, 

but usually may not reverse a trial court’s ruling on any theory or basis that might have 

been applicable to the case, but was not raised”). Here, it does not appear from the record 

that the State ever advanced mistake of law as an alternative theory to justify the 

reasonableness of the officer’s conduct. There was only a brief statement during the motion 

to suppress hearing where the State argued, in the middle of its closing, that:

. . . knowing that he [the officer] was looking for something to stop [her] for, 

in his mind what was important in his report was the immediate cause that 

he was stopping [her] for, which was – he believed it was a violation for [her]

to swerve into that lane and come back. Whether it is or isn’t, that was what 

he believed was the immediate cause for the stop. And that’s how he wrote 

his report. 

This argument potentially alludes to the fact that the officer did not have to be correct about 

the law, so long as any mistake was reasonable. But this argument was too implicitly stated 

to plausibly raise a mistake-of-law issue here. Indeed, there was never any explicit 

argument regarding mistake of law, and neither the trial judge nor opposing counsel 
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addressed nor acknowledged the State’s brief allusion to the officer’s understanding of the 

law, whether right or wrong. Even now on discretionary review, the State does not argue 

in its brief to this Court that mistake of law should apply or that it should even be permitted 

at this juncture to argue that it does.

Thus, recognizing that mistake of law was not properly raised in this case, I agree 

with the Court’s implicit determination that, although apparently meritorious, that 

argument cannot now serve as a basis to reverse the trial court’s suppression ruling. With 

these comments, I join the Court’s opinion upholding the trial court’s suppression ruling.

Filed: November 2, 2022

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