United States v. Adam Daniel‑DeJesus Santos: Officer‑Safety Questioning and Frisk of a Passenger’s Cross‑Body Bag as “Negligibly Burdensome Precautions” During a Traffic Stop

I. Introduction

In United States v. Adam Daniel‑DeJesus Santos, No. 25‑1051 (6th Cir. Dec. 16, 2025), a published opinion authored by Chief Judge Sutton, the United States Court of Appeals for the Sixth Circuit addressed a recurring Fourth Amendment problem:

When does questioning or investigative activity during a traffic stop “unreasonably prolong” the stop?
What level of suspicion allows officers to frisk a passenger and manipulate or open a bag worn on the passenger’s body?
How do consent to search the vehicle and officer‑safety concerns interact with the limits imposed by Rodriguez v. United States?

The case arose from a Michigan State Trooper’s stop of a car for expired registration, discovery that the passenger (Santos) had violent felony convictions and was flagged as “possibly armed,” and a subsequent frisk that revealed a firearm in Santos’s cross‑body bag. Santos, a felon, was indicted for unlawful possession of a firearm under 18 U.S.C. §§ 922(g)(1) and 924(a)(8). He moved to suppress the gun as the product of an unconstitutional seizure and search.

The district court denied the motion, and the Sixth Circuit affirmed. In doing so, the court clarified and, in practical terms, broadened the scope of “negligibly burdensome precautions” that officers may undertake during a traffic stop under Rodriguez v. United States, especially when a database flags a passenger as “possibly armed” and the passenger exhibits suspicious behavior. The court also underscored that a Terry frisk can include manipulating and opening a bag worn on a person’s body once the officer feels a weight consistent with a weapon.

II. Summary of the Opinion

A. Factual Background

On May 19, 2024, Michigan State Trooper James Fabijancic stopped a black Chevrolet after observing expired registration tags. Before activating his lights, he noticed the passenger, Adam Santos, repeatedly turning and looking back at the patrol car—behavior the trooper interpreted as nervous or watchful.

During the initial encounter:

The trooper asked the driver for her license, registration, and insurance, and asked Santos for his license.
Santos searched around his seat and underneath himself, but conspicuously did not look into the cross‑body bag he was wearing across his chest. He claimed he could not find his license but supplied his name and date of birth.
The trooper returned to his cruiser and ran checks. He confirmed the expired registration and learned that Santos had prior convictions for assault with a dangerous weapon and armed robbery, was on probation, and was associated with an audible system alert: “26‑year‑old male, possibly armed, if arrested call dispatch.”
He called for backup.

The trooper then:

Asked the driver to exit, walked her to the rear of the car, and requested—and received—consent to frisk her for weapons.
Briefly asked her whether she had weapons, drugs, heroin, or meth, and whether there were weapons or drugs in the car; she said no.
Asked if he could search the vehicle; she agreed. This colloquy lasted about 40 seconds.
Explained the expired registration and how to renew it, noting she was a first‑time car owner. He retained her license during this interaction.
Told her to “hang tight,” then asked Santos to step out, confirmed he was on probation, and asked whether he had any weapons. Santos replied no.
Asked, “you don’t mind if I check, do you?”, and Santos indicated “no” with his head (an ambiguous gesture, but the court ultimately deemed consent unnecessary).
Frisked Santos, including shifting the cross‑body bag from Santos’s chest to his back. Upon moving the bag, the trooper felt a weight consistent with a firearm and began unzipping the bag.
At that moment, Santos tried to break away, leading to a scuffle, Santos’s arrest, and the discovery of a gun in the bag.

A grand jury indicted Santos for being a felon in possession of a firearm. He moved to suppress the firearm as the fruit of unlawful prolongation of the stop and an unlawful frisk and bag search. The district court denied suppression and later sentenced him to 27 months’ imprisonment.

B. Issues Presented

On appeal, Santos raised two primary Fourth Amendment challenges:

Prolongation of the stop: Did the trooper unreasonably prolong the traffic stop beyond its lawful “mission” when he:
- Took the driver to the rear of the vehicle,
- Asked about weapons and drugs,
- Requested consent to search the vehicle, and
- Separated the driver and Santos?
Search of Santos’s person and bag:
- Did the trooper have adequate legal justification (reasonable suspicion) to frisk Santos?
- Did the frisk lawfully extend to manipulating and then opening the cross‑body bag?
- Was Santos’s consent to the frisk (if any) voluntary, and was consent needed at all?

C. Holding

The Sixth Circuit affirmed the district court’s denial of Santos’s motion to suppress and upheld the conviction:

The expired registration gave probable cause for the stop.
The trooper’s 40‑second questioning of the driver about weapons and drugs, his request to search the vehicle, and his separation of driver and passenger did not unreasonably prolong the stop because:
- They were “negligibly burdensome precautions” directly related to officer safety under Rodriguez, and
- By the time of these actions, the trooper had reasonable suspicion that Santos was armed and dangerous, justifying heightened safety measures.
The frisk of Santos, including moving the cross‑body bag, was supported by reasonable suspicion that he was armed and dangerous.
Once the trooper felt a weight in the bag consistent with a firearm, he had probable cause to open the bag and remove the weapon under the “plain feel” doctrine.
Santos’s consent to the frisk was not necessary to uphold the search, given the pre‑existing reasonable suspicion. In any event, Santos had not shown his consent was involuntary.
The driver’s consent to search the vehicle was voluntary under the totality of the circumstances; mere retention of her license during the stop did not render her consent coerced.

III. Detailed Analysis

A. Precedents and Doctrinal Foundations

1. Traffic Stop Scope and Duration

The opinion is anchored in the Supreme Court’s modern traffic‑stop jurisprudence:

Rodriguez v. United States, 575 U.S. 348 (2015):
- Core rule: A traffic stop may last only as long as necessary to address the traffic violation and “attend to related safety concerns.”
- Officers may not measurably extend a stop to pursue unrelated investigations (e.g., a dog sniff) without independent reasonable suspicion.
- However, they may take “certain negligibly burdensome precautions” to complete the mission safely.
Atwater v. City of Lago Vista, 532 U.S. 318 (2001): Probable cause to believe a traffic offense occurred (here, expired registration) justifies a stop.
Pennsylvania v. Mimms, 434 U.S. 106 (1977): Officers may order a driver out of the vehicle during a lawful stop as a safety measure.
Maryland v. Wilson, 519 U.S. 408 (1997): Extends Mimms—officers may order passengers to exit as well.
Ohio v. Robinette, 519 U.S. 33 (1996): No per se rule that an officer must tell a motorist they are “free to go” before asking for consent; consent can be voluntary even while the motorist remains seized.
Arizona v. Johnson, 555 U.S. 323 (2009) (cited indirectly): Recognizes the particular danger of traffic stops and authorizes frisking a passenger during a lawful stop if the officer reasonably suspects the person is armed and dangerous.

The Sixth Circuit overlays its own precedents on this framework:

United States v. Smith, 601 F.3d 530 (6th Cir. 2010): Officers may request identification from passengers during a lawful stop.
United States v. Williams, 68 F.4th 304 (6th Cir. 2023): Permits limited, “context‑framing” questions about travel plans and activities.
United States v. Whitley, 34 F.4th 522 (6th Cir. 2022): Emphasizes that officers may not abandon a traffic stop’s mission to pursue a separate investigation absent reasonable suspicion; also cautions against removing passengers from a vehicle for reasons unrelated to the stop without independent reasonable suspicion.
United States v. Lott, 954 F.3d 919 (6th Cir. 2020): “Safety measures taken to facilitate a different investigation . . . are not tasks incident to the initial stop.”
United States v. Blair, 524 F.3d 740 (6th Cir. 2008): A simple request to search a vehicle does not, standing alone, unlawfully prolong a traffic stop.
United States v. Moffitt, 2025 WL 2702495 (6th Cir. Sept. 23, 2025): Reinforces that whether questions fall within the proper duration of a traffic stop is a context‑specific inquiry.

The court also refers to the standard‑of‑review case United States v. Whitley (for de novo review of law, clear error for fact) and United States v. Stepp, 680 F.3d 651 (6th Cir. 2012), to remind that appellate courts view facts in the light most favorable to the prevailing party on a suppression motion.

2. Reasonable Suspicion and the “Totality of the Circumstances”

On the reasonable‑suspicion front, several Supreme Court precedents are invoked or relied upon:

Illinois v. Wardlow, 528 U.S. 119 (2000): Reasonable suspicion requires more than a hunch but less than probable cause; it is satisfied by a “minimal level of objective justification.”
United States v. Sokolow, 490 U.S. 1 (1989): Courts must consider the “totality of the circumstances”; individual factors, perhaps innocuous in isolation, can collectively amount to reasonable suspicion.
Ornelas v. United States, 517 U.S. 690 (1996): Encourages “commonsense” judgments rather than rigid rules when assessing reasonable suspicion and probable cause.
United States v. Arvizu, 534 U.S. 266 (2002): Warns against a “divide‑and‑conquer analysis” that examines each factor in isolation rather than in aggregate.

Sixth Circuit cases further refine this standard:

United States v. Jordan, 100 F.4th 714 (6th Cir. 2024): A passenger’s nervousness can be more probative than a driver’s nervousness in the reasonable‑suspicion analysis.
United States v. Pacheco, 841 F.3d 384 (6th Cir. 2016): Furtive movements near areas where firearms are commonly concealed (e.g., under the seat, within reach) support reasonable suspicion.
United States v. Peake‑Wright, 126 F.4th 432 (6th Cir. 2025): A passenger’s abrupt removal of a jacket in freezing temperatures can suggest the jacket hides contraband; another illustration of behavior that, in context, bolsters suspicion.
United States v. Stepp, 680 F.3d 651 (6th Cir. 2012): A person’s criminal history can support reasonable suspicion when it is “specific and related to the same suspicions that the officer was developing.”

3. Terry Stops, Frisks, and Plain‑Feel Doctrine

The search of Santos’s person and bag is governed by the lineage of Terry:

Terry v. Ohio, 392 U.S. 1 (1968): Allows an officer to conduct a limited pat‑down (frisk) of a person if the officer has reasonable suspicion that the individual is armed and dangerous; the aim is officer safety, not evidence‑gathering per se.
Minnesota v. Dickerson, 508 U.S. 366 (1993): “Plain feel” doctrine: if, during a lawful frisk, an officer feels an object whose incriminating character is immediately apparent (e.g., the shape or weight of a gun), the officer may seize it; if that object is within a container worn on the body, opening that container may be justified.

The opinion cites Dickerson directly for two points:

Law enforcement may conduct a protective search of the person when they reasonably suspect the person is armed and dangerous.
If, during the pat‑down, the officer feels the familiar shape or weight of a weapon, that gives probable cause to seize and open the container.

4. Consent Searches

Consent doctrine undergirds the vehicle‑search aspect:

United States v. Wellman, 185 F.3d 651 (6th Cir. 1999), and United States v. Tellez, 86 F.4th 1148 (6th Cir. 2023): Uphold voluntary consent to search given during an ongoing, lawful traffic stop.
United States v. Blair, 524 F.3d 740 (6th Cir. 2008): A request to search, by itself, does not extend the stop beyond its permissible scope.
United States v. Calvetti, 836 F.3d 654 (6th Cir. 2016) (Suhrheinrich, J., concurring): Recognizes that a request to search is effectively a request to extend the stop—but the driver may decline.
United States v. Salkil, 10 F.4th 897 (8th Cir. 2021) (cited for persuasive authority): Similar understanding that a request to search need not unlawfully prolong the stop.
Ohio v. Robinette, 519 U.S. 33 (1996): Confirms that consent may be voluntary even where the person remains seized and even if the officer has just returned (or retained) a driver’s license.

The Santos court notes that Santos failed to provide Sixth Circuit precedent holding that retention of a driver’s license, by itself, renders consent involuntary. The opinion instead relies on the totality‑of‑the‑circumstances test and prior cases upholding consent during ongoing stops.

B. The Court’s Legal Reasoning

1. Standard of Review

The court applies:

De novo review to the district court’s Fourth Amendment conclusions.
Clear‑error review to the district court’s factual findings.

Crucially, any factual disputes are resolved in favor of the district court’s ruling (here, against Santos), consistent with Whitley and Stepp. This posture matters because the appellate court explicitly “view[s] this constellation of circumstances in the light most favorable to the government.”

2. Did the Trooper Unreasonably Prolong the Stop?

a. Lawful initiation and basic tasks

The initial seizure was unquestionably lawful:

Expired tags provided probable cause under Atwater.
The trooper’s requests for the driver’s and Santos’s licenses fit within Smith and Williams.
Checking licenses, verifying registration, and running warrant/criminal‑history checks are core parts of the traffic stop “mission” under Rodriguez.

At this stage, nothing the trooper did deviated from the conventional script of a traffic stop.

b. Development of reasonable suspicion and safety concerns

The key shift occurs once the trooper receives:

Confirmation of Santos’s violent felony convictions (assault with a dangerous weapon; armed robbery).
Notice that Santos is on probation.
An audible alert that Santos is “possibly armed” and that officers should call dispatch if he is arrested.

The trooper also observed:

Santos’s repeated “nervous glances” at the patrol vehicle before the stop—behavior that, under Jordan, counts more heavily for a passenger than for a driver.
Santos’s “furtive behavior” with respect to his cross‑body bag: he searched everywhere for his license except the bag across his chest, “the first place one would expect him to look.” The court analogizes this to:
- Pacheco (rummaging/glancing around areas where firearms are often concealed), and
- Peake‑Wright (sudden removal of a jacket despite freezing temperatures, suggesting the jacket might hide contraband).

Adding Santos’s violent criminal history and probationary status—“specific and related to the same suspicions” about weapons (Stepp)—the court concludes that, under the totality of the circumstances, the trooper had reasonable suspicion that Santos might be armed and dangerous.

This reasonable suspicion justified:

Calling for backup.
Separating the driver from Santos by asking her to step to the rear of the vehicle.
Asking questions aimed at confirming or dispelling the risk from weapons and contraband in the car.

c. Officer‑safety questioning and the 40‑second exchange

Santos argued that the 40‑second conversation with the driver—asking about weapons and drugs and requesting consent to search—went beyond the limited “mission” of the traffic stop and unlawfully prolonged the seizure.

The Sixth Circuit’s answer has two main components:

Unclear if there was any measurable prolongation at all:
- The trooper had not yet completed the “enforcement action” of the stop (here, a warning combined with an explanation of registration renewal) when he spoke with the driver at the rear of the car.
- The exchange took about 40 seconds, and backup had not yet arrived.
- On these facts, the court suggests the questioning may have occurred within the ordinary time frame needed to execute the traffic stop tasks.
Even if it did extend the stop, the extension was justified as an officer‑safety measure:
- Rodriguez expressly allows officers to “attend to related safety concerns” and to take “negligibly burdensome precautions” to complete the mission safely.
- The system alert that Santos was “possibly armed,” combined with his behavior and background, created more than a “hunch” under Wardlow and justified heightened caution.
- Bringing the driver to the back of the car allowed the trooper to control the scene and keep Santos in view, consistent with Mimms.
- The questions about weapons and drugs were framed as efforts to ensure there were no other “considerations that could heighten danger” during the stop, particularly when the trooper was outnumbered and on the roadside.

To reinforce that the questions were within the permissible scope, the court cites out‑of‑circuit cases that permit limited contraband questioning as part of officer‑safety measures:

United States v. Taylor, 60 F.4th 1233 (9th Cir. 2023).
United States v. Ross, 151 F.4th 487 (3d Cir. 2023).
United States v. Buzzard, 1 F.4th 198 (4th Cir. 2021).

While some of the questions expressly referenced drugs (“heroin or meth or nothing like that?”), the court subsumes even these under officer safety, reasoning that discovering drugs or related contraband can bear on the potential volatility of the encounter.

d. Separating driver and passenger; request for vehicle search

The opinion treats two related actions as lawful:

Ordering the driver and passenger out of the car:
- Authorized under Mimms and Wilson as standard officer‑safety measures.
- Here, the trooper’s decision to speak to the driver away from Santos was specifically justified by the information that Santos was “possibly armed.”
Requesting consent to search the car:
- Under Blair, a simple request to search does not in itself prolong the stop beyond its permissible scope.
- A request is inherently one the driver can accept or decline; under Calvetti (concurring) and Salkil, the request is not automatically an extension of the stop in the constitutional sense.

Once the driver consented, it was permissible to remove Santos from the car to conduct the vehicle search safely, again consistent with Wilson.

e. Distinguishing Whitley, Moffitt, and Lott

Santos heavily relied on three Sixth Circuit decisions to argue that the trooper had crossed the line.

Whitley (34 F.4th 522)

In Whitley, officers saw a digital scale during a traffic stop and “abandoned” the traffic mission to investigate drugs, without then having reasonable suspicion.
The Sixth Circuit found that the officers had strayed beyond “negligibly burdensome precautions” and improperly prolonged the stop until further facts developed reasonable suspicion.
Santos argued that his case was similar, depicting the questions about drugs and weapons as an unrelated drug investigation.
The court distinguished Whitley on two grounds:
- Unlike in Whitley, the trooper here had explicit, documented reason to believe Santos was “possibly armed” and dangerous; the officers in Whitley had no such safety flag for weapons.
- The intrusion in Whitley was more extensive than the 40‑second questioning here, which the court characterized as a “negligibly burdensome precaution” centered on safety.
The court also notes that Whitley is not the “Rosetta Stone” Santos claimed: ultimately, that case upheld the dog‑sniff search once reasonable suspicion matured, underscoring that stops may be extended when supported by adequate suspicion.

Moffitt (2025 WL 2702495)

Moffitt recognized that whether questions are within the proper duration of a traffic stop is context specific.
The court emphasizes that, in Moffitt, there was no suspicion regarding weapons; by contrast, the “context” in Santos—armed‑and‑dangerous alert, violent history, suspicious behavior—was significantly more fraught.

Lott (954 F.3d 919)

Lott cautioned that “safety measures taken to facilitate a different investigation . . . are not tasks incident to the initial stop.”
Santos invoked this to argue that the trooper’s inquiries about heroin and meth reflected a separate drug investigation, not safety.
The court responds that here, the safety measures—including questions about weapons and drugs—were tightly bound to the existing stop and to the specific risk that Santos posed. The questions were not a pretext to launch an unrelated narcotics investigation.

f. Driver’s consent and retention of her license

Santos argued that the driver’s consent to search the vehicle was involuntary because the trooper retained her license throughout the stop, allegedly implying that her documents (and hence her freedom to go) depended on agreeing to the search.

The court rejects this argument for several reasons:

The district court made a factual finding that the trooper’s “ask” was “polite and friendly” and that the consent was voluntary under the “totality of the circumstances.”
Santos cited no Sixth Circuit case holding that retention of a license during a valid traffic stop, without more, coerces consent.
Sixth Circuit decisions like Wellman and Tellez have repeatedly upheld consent given during an ongoing stop.
Robinette rejected a bright‑line rule requiring officers to tell motorists they are “free to go” before requesting consent; in fact, Robinette upheld voluntary consent after the ostensible conclusion of a traffic stop.

Accordingly, the driver’s consent stands, and with it, the legality of ordering Santos out of the car to conduct a vehicle search safely.

3. Did the Trooper Unreasonably Search Santos?

a. Ordering Santos out of the vehicle

Once the driver consented to a vehicle search, the trooper was entitled to ask Santos to exit the car. The court cites Wilson (officers may order passengers out) and notes that removing Santos was integral to safely searching the interior of the vehicle.

b. Reasonable suspicion to frisk Santos

By this point in the encounter, the court holds that reasonable suspicion existed that Santos was armed and dangerous, based on:

The law enforcement database alert that Santos was “possibly armed.”
His violent felony history and probationary status.
His nervous glancing at the trooper before the stop.
His suspicious handling of the cross‑body bag when asked for his license.

Under Terry and Dickerson, this suspicion allowed a protective frisk “of [the individual’s] person” for weapons—without needing Santos’s consent.

The opinion treats the cross‑body bag as effectively part of Santos’s person for frisk purposes:

The bag was worn across his chest, intimately associated with his body and accessible to his hands.
A reasonable officer concerned with weapons would naturally frisk such a container as part of checking the person for arms.

C. Manipulating and opening the cross‑body bag

During the frisk, the trooper shifted the bag from Santos’s chest to his back. At that moment, he felt a weight consistent with a gun. That tactile impression, the court holds, gave the trooper probable cause to open the bag and retrieve the weapon under the Dickerson “plain feel” doctrine.

Santos did not directly contest the district court’s finding that opening the bag was justified once the trooper felt a weapon‑like weight. Instead, he attacked the frisk’s lawfulness and the lack of specific findings on the voluntariness of his consent to be frisked.

d. Role (and non‑role) of consent

The trooper had asked Santos, “you don’t mind if I check, do you?”, and Santos “indicated with his head no.” The record is ambiguous as to whether that nod meant “no, I do not mind (go ahead)” or “no, I don’t consent.” The appellate court resolves this ambiguity by deeming consent unnecessary for constitutional purposes.

The court’s reasoning:

No consent was needed: Once the trooper had reasonable suspicion that Santos was armed and dangerous, Terry permitted a frisk regardless of consent.
Santos did not explain how any consent he did give was involuntary under the totality‑of‑the‑circumstances test.
Even if Santos intended to withhold or later withdraw consent (by pulling away as the zipper opened), the trooper’s independent reasonable suspicion and subsequent probable cause (after feeling the gun‑like weight) justified the continued search for safety reasons.

In short, the court treats the frisk and bag opening as valid even assuming no consent, because they were supported by:

Reasonable suspicion before the frisk, and
Probable cause once the weapon‑like object was felt.

IV. Impact and Significance

A. Clarifying the Boundaries of “Negligibly Burdensome Precautions”

The central precedential contribution of Santos is its expansive and concrete application of the “negligibly burdensome precautions” language from Rodriguez. The decision treats a series of actions as within the permissible scope of the traffic stop when supported by safety‑based reasonable suspicion:

Separating driver and passenger.
Asking the driver about weapons and drugs in and around the vehicle.
Requesting consent to search the vehicle.
Ordering the passenger out of the vehicle for a consented vehicle search.
Frisking the passenger, including manipulating a bag worn on his body.

Future litigants in the Sixth Circuit will likely see Santos cited to:

Defend short (sub‑minute) lines of questioning about weapons and drugs where there is any articulable officer‑safety concern.
Justify separating vehicle occupants as a routine—and constitutionally permissible—safety tactic when one occupant is flagged as potentially armed or has a violent history.

B. Database Alerts and Criminal History as Drivers of Reasonable Suspicion

Santos underscores the weight courts will give to:

Computerized law‑enforcement alerts that a person is “possibly armed.”
Violent criminal histories and probation or parole status.

When combined with relatively subtle behavioral cues (like repeated backward glances and unusual handling of a bag), those data points can establish reasonable suspicion to:

Prolong the stop slightly for safety measures.
Conduct a Terry frisk of a passenger.
Expand the frisk to include containers worn on the body.

This strengthens law‑enforcement reliance on database information in real‑time policing decisions and provides prosecutors with a strong doctrinal anchor for justifying safety‑driven expansions of a stop.

C. Consolidating and Distinguishing Whitley, Lott, and Moffitt

The opinion helps harmonize prior Sixth Circuit decisions that might be read as limiting officer latitude:

Whitley and Lott stand for the proposition that officers cannot pivot from a traffic stop to an unrelated investigation without reasonable suspicion and cannot cloak unrelated investigations in the guise of “safety measures.”
Santos shows that once safety‑based reasonable suspicion does exist—especially about weapons—the court will interpret modest questioning and separation of occupants as properly incident to that stop, not as separate investigations.

In practice, this means defense challenges premised on “mission creep” will be harder to sustain when officers can articulate:

Specific, documented safety concerns (e.g., system alerts, criminal history related to violence), and
Observable behavior that reasonably heightens those concerns.

D. Frisking Bags and Other Personal Containers

By approving the manipulation and opening of Santos’s cross‑body bag during a frisk, the court implicitly:

Treats such a bag as an extension of the person for Terry purposes.
Affirms that once an officer feels a weapon‑like weight or shape in such a bag, probable cause justifies opening the bag without a warrant.

This has notable implications:

Officers may feel more confident frisking backpacks, satchels, and cross‑body bags worn on a suspect’s person when there is reasonable suspicion of weapons.
Defense arguments that officers must stop at the exterior feel of a bag, and may not open it absent consent or a warrant, will likely fail when the bag is worn on the body and the officer testifies to the “plain feel” of a weapon.

E. Consent Doctrine: No Bright‑Line Rule on License Retention

On the consent side, Santos reinforces several points:

Consent can be validly obtained during an ongoing traffic stop while the driver’s license is still in the officer’s possession.
Politeness, non‑threatening demeanor, and the absence of overt coercion remain central in evaluating voluntariness.
The burden to show coercion lies on the defendant; absent authority or concrete facts suggesting overbearing police tactics, courts will generally uphold consent findings.

For practitioners, the case suggests:

Defense counsel must marshal more than the bare fact of license retention to argue coercion.
Government counsel should build a record about tone, phrasing, and circumstances of the consent request to support totality‑of‑the‑circumstances findings.

V. Complex Concepts Simplified

1. “Probable Cause” vs. “Reasonable Suspicion”

Probable cause: A reasonable belief, based on facts, that a person has committed a crime or that evidence of a crime is present. It is a higher standard than reasonable suspicion and is required for arrests and most searches.
Reasonable suspicion: A lower standard—specific, articulable facts plus rational inferences that criminal activity may be afoot or that a person is armed and dangerous. Sufficient for brief stops and frisks (Terry), but not for full‑blown searches or arrests.

2. The “Mission” of a Traffic Stop and “Prolongation”

The “mission” of a traffic stop includes:
- Checking driver’s license and registration.
- Running warrant and criminal‑history checks.
- Issuing a citation or warning.
- Attending to related safety concerns (e.g., ordering occupants out of the car).
Unreasonable prolongation occurs when:
- Officers add time to the stop for tasks unrelated to this mission (like investigating unrelated drug crimes) without reasonable suspicion.
- Even short delays can be unlawful if they serve only investigatory purposes and not safety or mission‑related tasks.
Santos holds that a 40‑second set of questions about weapons and drugs, taken against the backdrop of a “possibly armed” alert, was a permissible safety measure, not an impermissible prolongation.

3. “Negligibly Burdensome Precautions”

This phrase comes from Rodriguez and refers to minor steps officers may take to protect themselves and others during a traffic stop, even if they add a small amount of time. Examples include:

Ordering occupants out of the car.
Separating individuals for brief questioning.
Asking simple questions about weapons.

Santos clarifies that such precautions can include brief questioning about drugs and contraband when there is a specific safety concern, such as a “possibly armed” alert.

4. Terry Frisks and the “Plain Feel” Doctrine

A Terry frisk is a limited pat‑down of a person’s outer clothing (and items worn on the body) for weapons, justified when an officer reasonably believes the person may be armed and dangerous.
The frisk is not a search for evidence; it is designed to protect the officer and others.
Under the plain feel doctrine (Minnesota v. Dickerson), if, during a lawful frisk, the officer immediately recognizes by touch that an object is a weapon (or contraband), the officer may seize it:
- No warrant or additional suspicion is required at that point.
- In Santos, feeling a weight consistent with a gun in a cross‑body bag provided probable cause to open the bag and seize the firearm.

5. Consent to Search

A search is lawful if a person with authority voluntarily consents, even without a warrant or probable cause.
Voluntariness is judged by all the circumstances, including:
- Presence of threats or commands.
- Number of officers and show of force.
- Whether the person was told they could refuse.
- Intoxication or comprehension issues.
A person can consent even while seized during a traffic stop; it does not automatically become coercive just because the officer holds their license.
In Santos, the driver’s consent to search the car was found voluntary, and consent from Santos himself was not necessary for the frisk and bag search because those were supported by reasonable suspicion and later probable cause.

VI. Conclusion

United States v. Santos is a significant published decision in Sixth Circuit Fourth Amendment law. It reinforces that:

Traffic stops may include modest officer‑safety measures—such as briefly questioning about weapons or drugs and separating occupants—without violating Rodriguez, especially when a database flags a passenger as “possibly armed” and other indicators (criminal history, behavior, probation status) heighten concern.
Reasonable suspicion that a passenger is armed and dangerous allows officers to frisk both the person and a bag worn on the body; feeling a weapon‑like object then justifies opening the bag under the plain‑feel doctrine.
Consent to search a vehicle given during an ongoing traffic stop can be voluntary even when the officer retains the driver’s license, absent additional coercive circumstances.

Practically, Santos gives law enforcement in the Sixth Circuit a clearer and somewhat broader safe harbor for officer‑safety actions during traffic stops, while offering guidance to courts and litigants on how to analyze brief questioning, consent, and on‑body container frisks under the Fourth Amendment. It will likely become a key reference point in future suppression litigation involving traffic stops, officer‑safety concerns, and the scope of permissible “negligibly burdensome precautions” under Rodriguez.