United States Court of Appeals For the First Circuit

No. 22-1579

UNITED STATES OF AMERICA,

Appellant,

v.

STEVEN POTTER,

Defendant, Appellee.

APPEAL FROM THE UNITED STATES DISTRICT COURT FOR THE DISTRICT OF NEW HAMPSHIRE

[Hon. Joseph N. Laplante, U.S. District Judge]

Before

Kayatta, Howard, and Montecalvo, Circuit Judges.

Alexander S. Chen, Assistant United States Attorney, with whom Jane E. Young, United States Attorney and Seth R. Aframe, Assistant United States Attorney, were on brief, for appellant. Judith Mizner, Assistant Federal Public Defender, for appellee.

August 22, 2023 HOWARD, Circuit Judge. In May 2021, a Hooksett, New

Hampshire police officer, Nicholas Kapteyn, stopped a vehicle for

failure to use a turn signal on a road that narrows from two lanes

to one lane. Steven Potter was a passenger in the car, and the

officer soon discovered that Potter had outstanding arrest

warrants. The officer arrested Potter and seized a bag from him,

which contained narcotics. Potter was ultimately charged with

possession with intent to distribute controlled substances.

Prior to his trial, Potter filed a motion to suppress

the items seized during the traffic stop, arguing that the stop

was unlawful because New Hampshire law did not require use of a

turn signal at the merge point on the roadway where the vehicle

was stopped. If no turn signal was required, Potter argued, the

officer lacked either probable cause to believe that a traffic

violation occurred or reasonable suspicion of criminal activity.

The district court granted the motion to suppress, agreeing with

Potter that the New Hampshire statute (N.H. Rev. Stat. § 265:45)

did not require a turn signal at the merge point. The government

filed an interlocutory appeal of that decision, which is now before

us for review. See

.

I.

In reaching its decision, the district court concluded

that "[i]n plain terms, the [New Hampshire] signaling statute

requires a signal before turning, changing lanes, or starting from

- 2 - a parked position." United States v. Potter,

(D.N.H. 2022). Because the statute enumerates three acts that

do require a signal, the court reasoned, the fact that it does not

include "merging, moving right or left, or travelling on a roadway

that narrows or merges from two lanes into one[] means that the

statute does not require drivers to use a signal in these three

circumstances."

.

In the direction that the vehicle was traveling, the

roadway at issue transitions from two lanes to one lane,

accompanied by a sign that illustrates an abrupt end to the right

lane and dotted lines approaching the point on the sign where the

right lane ends. The district court concluded that the sign "does

not resemble the actual roadway or the configuration of the

narrowing point." Potter,

. Rather, it

found, the actual roadway "merged two lanes into one," with "merge"

"signif[ying] traveling forward on a straight roadway that narrows

or blends two lanes into one."

. Before conducting the

traffic stop, Officer Kapteyn saw the vehicle travelling in the

right lane, then saw it "'start[] to merge left or move left' in

front of his cruiser after the dotted line distinguishing the two

lanes ended, without using a signal."

(alteration in

original). The court concluded that this situation did not require

the driver to complete a lane change -- a concept the court defined

based on "common, ordinary meaning" as "a departure from one lane

- 3 - and the entry into an adjacent, parallel lane."

. Since

the maneuver constituted a "merge" instead of a "lane change," no

turn signal was required. The district court further concluded

that the sign -- which the New Hampshire Department of Safety

Division of Motor Vehicles Driver's Manual describes as a warning

sign meaning "Lane Ends" -- "cannot serve to reimagine the physical

realities of the road" and "is consistent with the court's

description of two lanes blending, just as it is consistent with

the right lane ending, since the signs as defined in the Driver

Manual do[] not draw a distinction between these two scenarios."

at 412 n.20. The court also concluded that the statute was

unambiguous, so the officer's belief that a turn signal was

required was not an objectively reasonable mistake of law.

.

On appeal, the government does not challenge the

district court's conclusion that a turn signal was not required by

law. Instead, it argues that the stop was nevertheless justified

because the officer either made a reasonable mistake of fact or a

reasonable mistake of law (or both) when concluding that a turn

signal was required. We address these arguments in turn,

ultimately concluding that the stop was not objectively

reasonable.

II.

- 4 - In reviewing a grant of a motion to suppress, we review

the district court's legal conclusions de novo and findings of

fact for clear error. United States v. Reyes,

(1st

Cir. 2022); United States v. Orth,

(1st Cir.

2017).

"A traffic stop for a suspected violation of law is a

'seizure' of the occupants of the vehicle and therefore must be

conducted in accordance with the Fourth Amendment." Heien v. North

Carolina,

, 60 (2014) (citing Brendlin v. California,

(2007)). There may not be complete clarity

as to whether a stop for a traffic violation must be supported by

probable cause or reasonable suspicion. Compare United States v.

Miles,

(1st Cir. 2021) (a traffic stop for failing

to keep right except to pass "requires, at a bare minimum,

'reasonable suspicion'" (quoting Heien, 574 U.S. at 60)) with

Reyes,

("the decision to stop an automobile is

reasonable" under the Fourth Amendment "[w]here the police have

probable cause to believe that a traffic violation has occurred"

(quoting Whren v. United States,

(1996))).1

1The district court here noted that, "[t]o justify this type of seizure, the traffic stop must either be based on 'probable cause to believe that a traffic violation has occurred' or 'reasonably grounded' suspicion that 'criminal activity is afoot.'" Potter,

(first quoting Whren v. United States,

(1996); and then Arizona v. Johnson,

(2009)). The parties do not dispute this standard.

- 5 - However, the parties do not debate the standard and we need not

address the issue here, given that we ultimately conclude there

was no reasonable suspicion for the stop, and a lack of reasonable

suspicion necessarily entails a lack of probable cause.

"[S]earches and seizures based on mistakes of fact can

be reasonable," so long as the mistake is an objectively reasonable

one. Heien, 574 U.S. at 61, 66. Similarly, "reasonable suspicion

can rest on a mistaken understanding of the scope of a legal

prohibition." Id. at 60. As with mistakes of fact, such mistakes

of law must be objectively reasonable -- "an officer can gain no

Fourth Amendment advantage through a sloppy study of the laws he

is duty-bound to enforce." Id. at 66-67. When determining whether

a mistake is objectively reasonable, we "consider the facts

available to law enforcement personnel at the time of the [stop]."

United States v. Moran,

(1st Cir. 2019).

A. Mistake of fact

The government argues that it was reasonable for the

officer to rely on the traffic sign to conclude that the right

lane ended, that the vehicle had to change lanes to remain on the

road, and, therefore, that a turn signal was required. In support,

it points to two cases in which district courts held that it was

reasonable for officers to rely on posted signage when making

traffic stops. In United States v. Blackburn, a district court in

Oklahoma concluded that it was reasonable for an officer to rely

- 6 - on a posted speed limit of 45 miles per hour when pulling someone

over for driving 52 miles per hour in a construction zone, even

though the legal speed limit was officially 75 miles per hour.

No. 01–CR–86,

, at *4 (N.D. Okla. Feb. 20, 2002).

The court concluded that it was a reasonable mistake of fact for

the officer to believe that the posted speed limit accurately

reflected the legal speed limit.

Similarly, in United States

v. Miles, a Maine district court concluded that it was objectively

reasonable for an officer to believe that a "Keep Right Except to

Pass" sign was enforceable, whether or not it was. No. 2:18-cr-

00144,

, at *3 & n.3 (D. Me. July 17, 2019).

The government urges that the same reasoning should

apply here, given that the meaning of the posted warning sign is

"Lane Ends." If it was reasonable for the officer to rely on that

sign to assume that the right lane would, in fact, end,2 the

government argues, then it was reasonable for the officer to

believe that it was necessary for the vehicle to change lanes from

the right lane to the left lane to remain on the road. And if

such a "lane change" was required, the reasoning goes, it was

2The government makes no argument that the sign both declared which lane ended and trumped any belief to the contrary derived from observation of the actual road itself. Any such argument is therefore waived. See United States v. Zannino,

(1st Cir. 1990).

- 7 - reasonable for the officer to believe a turn signal was required

under New Hampshire law.

Unlike the cases the government cites in support of its

reasoning, however, this case involves a sign that is directly

contradicted by the configuration of the actual roadway. In the

aforementioned cases, the roadways presented no circumstances that

would conflict with the posted signs. There was thus no indication

that the posted speed limit or "Keep Right Except to Pass" signs

were incorrect. By contrast, here, the district court found that

"[t]he sign does not resemble the actual roadway or the

configuration of the narrowing point, which does not present a

termination of the right lane or require a lane change, abrupt

shift, or the crossing of a middle or dotted line." Potter,

. The government does not challenge this factual

determination.3 It merely argues that it was reasonable for the

officer to rely on the warning sign, even though the roadway

presented a different configuration. We find this argument to be

unavailing.

3 In its briefing, the government does question some of the district court's factual conclusions. For example, its reply brief asserts that "there is no dispute that . . . the right lane ended," but the district court explicitly found that the road "does not present a termination of the right lane." Potter,

. At no point does the government assert that it is arguing for reversal of those factual findings, and it does not argue the clear error standard required for reversal of factual findings, so we decline to disturb the district court's findings of fact.

- 8 - The government correctly acknowledged at oral argument

that there could be a situation in which there is sufficient

disparity between a road sign and the realities of the road such

that an officer's reliance on the sign would be unreasonable. But

that is the situation in this case. The unchallenged factual

findings of the district court, based in part on its first-hand

"view" of the narrowing point,4 were that the two northbound lanes

of the road "merge together and eventually narrow into a one-lane

road,"

; that "[b]efore the dotted line separating the

two lanes ends, there is a sign on the right side of the road

indicating that the two lanes become one," id.; that "[t]he sign

does not resemble the actual roadway or the configuration of the

narrowing point,"

; that "nothing like a lane change, or

even a traditional merge onto a roadway, is experienced or executed

by the driver" when passing through the narrowing point,

; and that "[a]fter progressing past the end of the divided

lanes, a driver just follows the 'outside' lines while continuing

in the same direction, as the two lanes gradually and almost

imperceptibly blend into one lane,"

The officer here thus had

more to rely on than an incorrect traffic sign -- he had a full

visual of the realities of the road and even testified to driving

4 Prior to the suppression hearing, the court took a "view" of the intersection by driving through it several times. Neither party objected to the court's view or moved to exclude it from consideration.

- 9 - through the intersection "a lot," so had prior familiarity with

the configuration. When confronted with a warning sign meaning

"Lane Ends" that depicted an abrupt end to the right lane and a

roadway that, as the district court found, involved a merging of

two lanes rather than either lane ending, it was not objectively

reasonable for the officer to rely on the sign to govern the

factual situation he was encountering.5

B. Mistake of law

The government next argues that it was a reasonable

mistake of law for Officer Kapteyn to believe that a turn signal

was required at the merge point. It argues that the district

court, in conducting its analysis, improperly focused on "its

notion of the facts (a lane narrowing requiring merging)," when it

should have focused on "whether the signaling statute requires a

driver to signal when her lane ends, and she must then move into

the remaining lane." In essence, the government is arguing that

the officer's mistake of law (in believing that a turn signal was

required) was reasonable in light of the officer's mistake of fact

(believing that the right lane ended). However, as we have

articulated, the officer's mistake of fact was not a reasonable

one given that the configuration of the road did not match the

5 Indeed, in response to the judge's characterization that it "feels . . . like it's sort of a long slow blend into a single lane," the officer stated that "[i]t does have a similar feeling to that."

- 10 - sign. The government meanwhile makes no argument that it would be

reasonable to believe the statute requires a turn signal when lanes

merely "blend." Accordingly, because we reject the government's

mistake-of-fact argument, we need not address whether any mistake

of law was reasonable.

Based on the foregoing, we affirm the district court's

decision granting Potter's motion to suppress and remand the case.

- 11 -