Reply Brief — Donna Elizabeth Summers, Petitioner v. Montana

No. 25-588

In the Supreme Court of the United States

DONNA ELIZABETH SUMMERS, PETITIONER,

v.

STATE OF MONTANA, RESPONDENT.

ON PETITION FOR A WRIT OF CERTIORARI TO THE

SUPREME COURT OF THE STATE OF MONTANA

REPLY BRIEF FOR PETITIONER

ELIZABETH NIELSON

FRED A. ROWLEY, JR.

Wilson Sonsini

Counsel of Record

Goodrich & Rosati, P.C. MARK R. YOHALEM

95 S. State St., Ste 1000 MADELYN CHEN

Salt Lake City, UT 84111 Wilson Sonsini

Goodrich & Rosati, P.C.

KELSEY C. CATINA

953 E. Third St., Ste 100

Wilson Sonsini

Los Angeles, CA 90013

Goodrich & Rosati, P.C.

(323) 210-2900

701 Fifth Ave., Ste 5100

fred.rowley@wsgr.com

Seattle, WA 98104

PETE WOOD

1604 N. 30th St.

Boise, ID 83703

JOHN B. KENNEY

ABIGAIL HERMES

Wilson Sonsini

Goodrich & Rosati, P.C.

1700 K St. NW, 5th Floor

Washington, DC 20006

Counsel for Petitioner

TABLE OF CONTENTS

Page

INTRODUCTION ....................................................... 1

I.

It remains unsettled whether an officer

continues to seize a motorist by seamlessly

transitioning from a traffic stop to unrelated

questioning. .......................................................... 3

II. The State begs the question in focusing on the

totality-of-the-circumstances test. ...................... 6

III. The split is real and persistent. .......................... 8

IV. This is a clean vehicle. ....................................... 12

CONCLUSION ......................................................... 13

ii

TABLE OF AUTHORITIES

Page(s)

Cases

Ferris v. State,

735 A.2d 491 (Md. 1999) .................................1-2, 9

Florida v. Bostick,

501 U.S. 429 (1991) .............................................3-6

Illinois v. Caballes,

543 U.S. 405 (2005) ................................................ 7

Illinois v. Gates,

462 U.S. 213 (1983) ................................................ 6

Kansas v. Glover,

589 U.S. 376 (2020) ................................................ 6

Ohio v. Robinette,

519 U.S. 33 (1996) .................................................. 4

Ornelas v. United States,

517 U.S. 690 (1996) ................................................ 7

Rodriguez v. United States,

575 U.S. 348 (2015) ..................................... 2, 4-5, 7

Schneckloth v. Bustamonte,

412 U.S. 218 (1973) ................................................ 7

Shaw v. Smith,

166 F.4th 61 (10th Cir. 2026) .................. 3, 7, 9, 12

State v. Barks,

128 S.W.3d 513 (Mo. 2004) .................................... 9

State v. Hansen,

63 P.3d 650 (Utah 2002) ........................................ 9

State v. Robinette,

685 N.E.2d 762 (Ohio 1997).................... 1, 3-4, 8-9

iii

State v. Spies,

575 P.3d 708 (Haw. 2025) ...................................... 4

State v. Thompson,

166 P.3d 1015 (Kan. 2007) ................................. 1, 5

United States v. Bradford,

423 F.3d 1149 (10th Cir. 2005) ...........................8-9

United States v. Brown,

355 F. App’x 36 (7th Cir. 2009) ........................... 11

United States v. Clarke,

902 F.3d 404 (3d Cir. 2018) ................................. 10

United States v. Lattimore,

87 F.3d 647 (4th Cir. 1996) .................................. 11

United States v. Ramirez,

476 F.3d 1231 (11th Cir. 2007) .......................11-12

United States v. Richardson,

385 F.3d 625 (6th Cir. 2004) ................................ 10

United States v. White,

81 F.3d 775 (8th Cir. 1996) .............................11-12

United States v. Whitley,

34 F.4th 522 (6th Cir. 2022) ................................ 10

United States v. Williams,

784 F. App’x 876 (5th Cir. 2019).......................... 11

Other Authorities

George M. Dery III, “When Will This Traffic

Stop End?”: The United States Supreme

Court’s Dodge of Every Detained

Motorist’s Central Concern-Ohio v.

Robinette, 25 Fla.St.U.L.Rev. 519 (1998) ......... 1, 4

iv

4 W.R. LaFave,

Search & Seizure: A Treatise on the Fourth

Amendment (6th ed. 2024) ........................ 3-4, 8, 11

INTRODUCTION

The State’s refrain is that “settled Fourth Amendment rules” (BIO1) resolve whether police effect a seizure when they conclude a traffic stop’s purpose, then

“immediate[ly] transition into [an] inquiry” about contraband and request to search, Ferris v. State, 735

A.2d 491, 503 (Md. 1999). But that insistence cannot

overcome the chorus of concern about the very “analytical gap” that the State dismisses (BIO14) and this

Court’s Robinette decision left open. Because Robinette “did not address” the “blurring of the transition

from detention to consensual encounter,” State v.

Thompson, 166 P.3d 1015, 1035 (Kan. 2007), and left

open this “continuing seizure” question, the “Court

missed the opportunity to clarify an area of the law

suffering from uncertainty,” George M. Dery III,

“When Will This Traffic Stop End?”: The United States

Supreme Court’s Dodge of Every Detained Motorist’s

Central Concern-Ohio v. Robinette, 25 Fla.St.U.L.Rev.

519, 565 (1998). That confusion persists today.

The State fares no better with its other arguments

against review. In suggesting that the only alternative to the current confusion is a “categorical rule”

yielding “rigid per se commands” (BIO2), the State

presents a false choice. As illustrated by the dissent

below, this Court can furnish critical guidance without “elevat[ing]” the “temporal proximity” between a

traffic stop and further questioning into a “dispositive

test.” Ibid. The petition—like lower courts and commentators—asks only that the Court clarify whether

an officer improperly prolongs a roadside detention

where, as here, his transition from completed stop to

questioning is “so seamless that a reasonable motorist

2

would not have believed that the initial, valid seizure

had concluded.” Ferris, 735 A.2d at 503.

The dissent and like-minded courts hold that an

“officer’s immediate continuation of questioning”

may—“coupled with” his words and actions—convey

“ongoing investigative authority.” Pet.App.26a. The

majority and like-minded courts give inadequate

weight to that practice and the risk of “cloud[ing] a

[motorist’s] understanding,” treating the continued

questioning as consensual. Pet.App.21a. Resolving

that debate would clarify the responsibilities and promote the safety of officers and motorists alike, particularly because consent searches following traffic stops

“are now a wholesale activity” and the subject of police

training. Pet.App.21a-22a.

The State glosses over both the doctrinal gap on,

and conflict over, seamless stop-to-questioning transitions by invoking the totality-of-the-circumstances

test—46 times. This argument proves too much. If, as

the State suggests, the totality-of-the-circumstances

inquiry that applies across Fourth Amendment contexts supplied the controlling “legal standard” (e.g.,

BIO25), the Court would never need to articulate or

clarify substantive search-and-seizure standards. Yet,

this Court routinely grants review for that very purpose—including to address “the tolerable duration of

police inquiries in the traffic-stop context.” Rodriguez

v. United States, 575 U.S. 348, 354 (2015).

The State’s effort to harmonize the conflicting

cases as resting on “the identical” totality-of-the-circumstances inquiry (BIO25) thus falls apart. Of

course these cases all undertake a totality-of-the-circumstances inquiry. And of course that inquiry is

aimed at determining whether a reasonable motorist

3

would feel “free to decline the officers’ requests.” Florida v. Bostick, 501 U.S. 429, 439 (1991). But these

courts widely diverge on whether a motorist would

feel “compelled to submit to the officer’s questioning”

if it immediately follows a completed traffic stop. State

v. Robinette, 685 N.E.2d 762, 771 (Ohio 1997) (Robinette III).

Finally, the State’s vehicle challenge based on

“clear-error review” (BIO30) is foreclosed by the Montana Supreme Court’s rehearing order and the State’s

own brief to that Court. At the State’s insistence, that

court made clear it “applied a de novo review”

(Rhrg.Opp.2), and “reviewed the record independently”

(Pet.App.29a) to resolve the legal question whether

Summers was seized when she gave consent. And

“whether there has been a consensual encounter after

a highway traffic stop and return of the driver’s documents is one circumstance when an appellate ruling

in one case can provide substantial guidance in many

circumstances.” Shaw v. Smith, 166 F.4th 61, 85 (10th

Cir. 2026).

I. It remains unsettled whether an officer continues to seize a motorist by seamlessly transitioning from a traffic stop to unrelated

questioning.

Montana’s insistence that “settled Fourth Amendment rules” already resolve the question presented

(BIO1) is belied by this Court’s precedents, lower

court decisions, and leading commentary. Those

sources confirm that “whether a traffic offender somehow becomes ‘unseized’ upon return of his license notwithstanding a continuation (albeit on a different subject) of police discussion with the stopped driver” remains a flashpoint of disagreement. 4 W.R. LaFave,

4

Search & Seizure: A Treatise on the Fourth Amendment, § 9.3(h) (6th ed. 2024).

1. The State agrees that this question intersects

two lines of authority. On one hand, under Rodriguez,

“‘[a]uthority for [a traffic-stop] seizure…ends when

tasks tied to the traffic infraction are’ done.” BIO11

(quoting 575 U.S. at 354). On the other (BIO27-28), a

motorist is not seized by “mere police questioning” unless a “reasonable person” would not feel “free to decline the officers’ requests or otherwise terminate the

encounter[,]” Bostick, 501 U.S. at 434, 439.

The State concedes that under these principles,

“when a traffic stop ends and the officer asks additional unrelated questions, the interaction becomes either a consensual conversation or a coercive seizure.”

BIO12. To a reasonable motorist, however, the line between compulsion and consent may not be obvious

where, as here, an officer eschews “good police practice” by not telling the motorist “they are free to go.”

Pet.App.22a. Such “transition[s] between detention

and a consensual exchange can be so seamless that

the untrained eye may not notice that it has occurred.”

State v. Spies, 575 P.3d 708, 728 (Haw. 2025).

That is exactly the situation that warrants review

and clarity. For decades, courts and commentators

have noted that this remains “an unresolved legal

question” (cf. BIO3), because Ohio v. Robinette

stopped short of “decid[ing] whether [the driver] remained seized during the request for permission to

search,” Dery, supra, at 541. Robinette left that “analytical gap” (BIO14) because the Court focused on invalidating a “per se” voluntariness requirement of “inform[ing] detainees that they are free to go,” 519 U.S.

33, 40-41 (1996). That is why the Ohio Supreme Court

5

remained free, on remand, to “reaffirm[] its prior conclusion that the extended detention was illegal.”

Thompson, 166 P.3d at 1035. And while this Court has

subsequently clarified adjacent issues—like non-consensual “investigation into other crimes” following a

stop, Rodriguez, 575 U.S. at 356—it has not analyzed

the “transition from detention to consensual encounter,” Thompson, 166 P.3d at 1035.

The 4-3 decision below illustrates why “straightforward application of this Court’s precedents” cannot

resolve the question presented. BIO1. Invoking Rodriguez and Bostick principles (BIO27-28), the majority

held that Detective Monaco did not prolong “the stop

after it concluded” because he “asked Summers a single question—if she would ‘mind’ answering some

questions” (Pet.App.18a). Applying these same principles, the dissent concluded that Monaco’s “phrase,

coupled with [his] immediate continuation of questioning, conveyed ongoing investigative authority.”

Pet.App.26a.

2. Addressing how “immediately transition[ing]

into further questioning” can continue a seizure (ibid.)

would hardly require the “bright-line rule” Montana

chides (BIO2). Summers is not asking this Court to

“elevate” “temporal proximity” into the “dispositive

test.” Ibid. After all, as the dissent below recognized,

an officer’s words and actions leading to the questioning—including any “authoritative positioning”—bear

critically on whether the transition was so “seamless”

and “immediate” that a reasonable driver would not

have felt “truly free to leave.” Pet.App.26a. The Court

should use this case to provide a framework for assessing—not ignoring—those facts, and determining

when a transition is so seamless and immediate that

6

it continues the detention. Cf. Kansas v. Glover, 589

U.S. 376, 386 (2020) (resolving recurring, general

Fourth Amendment question, while identifying salient factors).

II. The State begs the question in focusing on

the totality-of-the-circumstances test.

The “fact-bound” inquiry that Montana ultimately

deems controlling is “totality-of-the-circumstances review.” BIO20. By framing the test for “post-stop encounters” at this overarching level, Montana seeks

both to bury the question presented and cast every

traffic-stop decision as “apply[ing] the same test.”

BIO20-22. But the Court undertakes totality-of-thecircumstances review as its method of “inquiry” in virtually every Fourth Amendment context, e.g., Glover,

589 U.S. at 386—not as a substantive test obviating

context-specific standards.

It is indeed “well-settled” (BIO1) that courts examine the totality of the circumstances in a wide range

of search-and-seizure contexts, from warrant-based

searches, e.g., Illinois v. Gates, 462 U.S. 213, 238

(1983), to seizures of people, Bostick, 501 U.S. at 437.

But that method merely guides courts in applying the

controlling substantive standard, be it probable cause

(for warrants) or freedom to disregard the police (for

seizures). If, as Montana suggests, that general inquiry foreclosed any specific “legal conflict that warrants this Court’s review” (BIO26), the Court would

never take cases to formulate or clarify search-andseizure standards. Yet, the Court routinely does just

that, underscoring the need for appellate courts “to

maintain control of, and to clarify, the legal principles”

governing Fourth Amendment challenges. Ornelas v.

United States, 517 U.S. 690, 697 (1996).

7

More specifically, the Court has repeatedly

granted review in traffic-stop cases to provide guidance on the scope of permissible police action—including the very “temporal issues” Montana dismisses.

BIO2. In Illinois v. Caballes, for example, the Court

upheld a dog sniff during a traffic stop that did not

prolong “the duration of the stop.” 543 U.S. 405, 408

(2005). In Rodriguez, however, the Court invalidated

a dog sniff conducted—over motorist objection—after

“completion of a traffic stop.” 575 U.S. at 350. The seizure became unlawful because it “prolong[ed] the stop”

without “reasonable suspicion.” Id. at 355. Together,

these and related cases define a “temporal” principle

that governs traffic-stop seizures (cf. BIO2) and allows

certain police actions during a traffic stop, provided

they “do not measurably extend the duration of the

stop,” Rodriguez, 575 U.S. at 355. What the Court’s

precedents have yet to do, however, is provide similar

guidance on the transition from a completed traffic

stop to consensual questioning “into other crimes.” Cf.

id. at 349. That question warrants review not only because of the discord it has created, but also because of

its importance and pervasiveness. Pet.30-33.

Montana does not dispute that the traffic-stop scenario Summers faced is common, and the attendant

detention issues, recurring. Nor are the frequency and

implications of the scenario happenstance, for they result from a “standard investigat[ive] technique” that

is decades-old, Schneckloth v. Bustamonte, 412 U.S.

218, 231-232 (1973), and that police departments continue to refine, e.g., Shaw, 166 F.4th at 72 (reviewing

Kansas troopers’ “Two-Step” practice, involving “an

extension of a traffic stop for a round of seemingly innocuous question[ing]”). The “routine” nature of this

unresolved issue strengthens, rather than dampens

8

(BIO1), the need for review. As the majority below recognized, the “wholesale activity” of stop-based consent

searches carries the risk that police will “cloud[] [motorists’] understanding” of whether they remain “subject to the officer’s authority,” then leverage that confusion into “highly invasive”—and dangerous—consent searches. Pet.App.21a (quoting LaFave, § 9.3(e)).

III.

The split is real and persistent.

Montana tries to chalk up the split’s “differing outcomes” to “different facts” (BIO2), arguing that the

“same standard” leads to “different fact-bound outcomes” (BIO25). Not so. Courts instead “reach[] different conclusions as they confront” the same basic scenario presented here. Cf. BIO26.

1. Compare Robinette III with United States v.

Bradford, 423 F.3d 1149 (10th Cir. 2005). Montana

says these decisions are in harmony because each undertook totality-of-the-circumstances review to determine whether the driver was detained (BIO18-19, 23),

but does not identify a single “different fact[]” that

could justify their “differing outcomes” (cf. BIO2).

Nor could it. Each driver was pulled over for a traffic infraction, then issued a “verbal warning.” Robinette III, 685 N.E.2d at 767; Bradford, 423 F.3d at

1154 (same). Each officer then “returned [the] driver’s

license,” before “seamlessly” transitioning into further

questioning. Robinette III, 685 N.E.2d at 764; Bradford, 423 F.3d at 1158-1159 (trooper “questioned her

after handing back her documents”). Yet as Montana

concedes, Robinette III focused “on the ‘troubling’ ‘immediate transition’ from the end of the traffic stop to

the unrelated questions” (BIO19), holding that it implied “Robinette was not free to go,” 685 N.E.2d at 770.

9

Conversely, Bradford upheld the immediate questioning because there was no additional “coercive show of

authority,” 423 F.3d at 1159, and the Tenth Circuit

recently reaffirmed that point, Shaw, 166 F.4th at 83

(quoting Bradford, 423 F.3d at 1159). The contrast between these two approaches—one deeming the immediate transition sufficient to seize, the other requiring

an “additional show of authority”—shows the difference is doctrinal, not factual. Cf. BIO18-19.

2. That comparison illustrates why Montana’s individual case summaries cannot explain the courts’

disparate outcomes—but for their disagreement over

the significance of an “immediate transition into the

[consent] inquiry.” Ferris, 735 A.2d at 503. Montana

again incants its totality-of-the-circumstances mantra,

stressing that Maryland, Utah, and Missouri all take

that approach. BIO18-20. But that is both unsurprising (supra § II) and beside the point. What matters is

that these courts all hold motorists detained when

post-stop questioning is “so seamless that a reasonable motorist” would not “believe[] that the initial, valid

seizure had concluded.” Ferris, 735 A.2d at 503; see

State v. Hansen, 63 P.3d 650, 662 (Utah 2002) (stressing “factual differences between the initial traffic stop

and the additional questioning were minimal”); State

v. Barks, 128 S.W.3d 513, 514-515 (Mo. 2004) (per curiam) (prolonged detention involved “constant” conversation).

Montana insists the Third Circuit does not support

our position because the “improper questioning in

[United States v.] Clarke occurred during the traffic

stop.” BIO17. But that is not how the Third Circuit

saw it. Rather, it framed the issue as whether “the

traffic stop must reasonably be seen as having been

10

completed before th[e unrelated] questioning began,”

then concluded the questioning was unlawful because

the “traffic stop was effectively completed.” 902 F.3d

404, 410-411 (3d Cir. 2018) (emphasis added).

It is equally irrelevant that the Sixth Circuit in

United States v. Richardson focused—like the dissent

here—on the officer’s “combination of directions and

words” rather than any “bright-line” consideration.

BIO16. Richardson held that the officer suggested the

driver “would not be free to walk away” by saying “just

hang out right here for me, okay” after “the traffic stop

[had] concluded,” then proceeding to question the passenger. 385 F.3d 625, 630 (6th Cir. 2004). And while

Montana relegates the follow-on decision in United

States v. Whitley, 34 F.4th 522, 529-530 (6th Cir.

2022), to a footnote, it confirmed that the officer’s unrelated questioning would have amounted to a “coercive seizure” had it occurred “after the traffic stop

ended” (cf. BIO16 n.1).

3. Conversely, the Fourth, Fifth, Seventh, Eighth,

and Eleventh Circuits, along with other states, allow

the same, post-stop questioning on materially identical facts. Pet.23-28. Montana again tries to cohere the

courts on this side of the split based on their totalityof-the-circumstances approach. BIO20-26. But it identifies no doctrinal basis for the jurisdictions’ “differing

outcomes” (BIO2) beyond their disagreement over the

question presented.

“Start with the Fourth Circuit” (BIO21), whose

United States v. Lattimore decision is “illustrative” of

courts that assume “returning [a motorist’s] credentials” marks a “clear line” between traffic stops and

consensual encounters. LaFave, § 9.3(h). The Fourth

Circuit placed critical weight not on the encounter’s

11

“friendly” tone (BIO21), but on the fact that the officer

“did not question Lattimore concerning the presence

of narcotics or contraband” until “after [he] had issued

the citations and returned Lattimore’s driver’s license,” 87 F.3d 647, 653 (4th Cir. 1996) (en banc).

The Fifth Circuit in Williams similarly stressed

that the officer had issued a “notice of violation” and

“returned [the motorist’s] driver’s license” before

“ask[ing] if he would keep talking.” United States v.

Williams, 784 F. App’x 876, 881 (5th Cir. 2019). Indeed, the State concedes the Fifth Circuit required

some additional “coercive step” beyond these actions

to deem the motorist seized. BIO22. That aligns the

Fifth Circuit not only with the Fourth and Tenth Circuits, but also the Seventh Circuit, which has likewise

held questioning consensual because it “transpired in

less than one minute after [the officer] issued the

warning to [the motorist] and returned his…license.”

United States v. Brown, 355 F. App’x 36, 38-39 (7th

Cir. 2009). The court’s determination that this exchange “only briefly extended the length of the stop”

was hardly “a stray line” (BIO22); it grounded the

court’s detention holding.

Montana again pushes at an open door in touting

the totality-of-the-circumstances approach taken in

United States v. White, 81 F.3d 775, 779 (8th Cir.

1996), and United States v. Ramirez, 476 F.3d 1231,

1240 (11th Cir. 2007). BIO23-24. Regardless of

whether these decisions noted “the details of the environment” or “more than timing” (ibid.), they both held

that police converted “a traffic stop into a consensual

encounter” when they proceeded directly to unrelated

questioning “after [the driver] had been handed his

12

paperwork” and “the traffic citation.” Ramirez, 476

F.3d at 1240; accord White, 81 F.3d at 778-779.

IV. This is a clean vehicle.

The State does not contest that the facts are undisputed and the question presented dispositive. It protests only that this case is a “poor vehicle” because the

Montana Supreme Court supposedly applied “clearerror review.” BIO30. But the Montana Supreme

Court already addressed its standard of review on rehearing, explaining that it “reviewed the record independently” to “determine[] that the District Court

finding was not erroneous…” Pet.App.29a. In arriving

at that holding, it agreed with the State, which argued

that “[t]his Court applied a de novo review of whether

the district court applied the pertinent law to the

facts.” Rhrg.Opp.2 (emphasis added); see also

Rhrg.Opp.6. This only makes sense; as with other substantive search-and-seizure standards, courts “review

for clear error” the “findings regarding historical facts,”

but “review de novo” whether “those facts establish a

consensual encounter.” Shaw, 166 F.4th at 85-86 (citing Ornelas, 517 U.S. at 697-699). Regardless, the

State cannot avoid rehearing on one theory, then

adopt the opposite theory to avoid certiorari.

13

CONCLUSION

This Court should grant certiorari.

Respectfully submitted,

ELIZABETH NIELSON

FRED A. ROWLEY, JR.

Wilson Sonsini

Counsel of Record

Goodrich & Rosati, P.C. MARK R. YOHALEM

95 S. State St., Ste 1000 MADELYN CHEN

Salt Lake City, UT 84111 Wilson Sonsini

Goodrich & Rosati, P.C.

KELSEY C. CATINA

953 E. Third St., Ste 100

Wilson Sonsini

Los Angeles, CA 90013

Goodrich & Rosati, P.C.

(323) 210-2900

701 Fifth Ave., Ste 5100

fred.rowley@wsgr.com

Seattle, WA 98104

PETE WOOD

1604 N. 30th Street

Boise, ID 83703

JOHN B. KENNEY

ABIGAIL HERMES

Wilson Sonsini

Goodrich & Rosati, P.C.

1700 K St. NW, 5th Floor

Washington, DC 20006

Counsel for Petitioner

MARCH 2026