TENTH CIRCUIT DISCUSSES INVESTIGATIVE DETENTIONS AND DISSIPATION OF REASONABLE SUSPICION

On September 30, 2025, the Tenth Circuit Court of Appeals decided United States v. Campbell,[i] in which the court examined whether reasonable suspicion to detain Campbell dissipated prior to the officer conducting a frisk and locating a weapon.  The facts, taken directly from the case, are as follows:

Around 11:30 p.m. one night in July 2021, Teresa Cooper called 911 to report that her home security camera was showing a Black man and woman taking items from her back porch. About one minute after the conclusion of that call, Officer Drew Mullinix arrived at the reported address, which was in a dimly lit residential area. As Mullinix exited his patrol vehicle, he saw a Black man—who later identified himself as Campbell—walking near some trash cans at the top of the driveway, near the back of the residence. From the other end of the driveway, Mullinix identified himself as law enforcement and instructed Campbell to come toward him.

Campbell did not comply with that instruction; instead, Campbell told Mullinix that he lived at the residence and walked toward a car parked in the driveway, facing the street, with the driver’s door open. The two men then talked over each other, with Mullinix repeating his “come here” instruction four more times, and Campbell repeating that he lived there three more times. As Campbell approached the car, Mullinix walked toward Campbell, telling him to keep his hands up. Campbell put his hands up, and Mullinix noticed a black magazine sticking out of Campbell’s waistband.2 Mullinix then had to repeat the hands-up instruction twice more for Campbell to keep his hands up. During these exchanges, Campbell was standing behind the open car door and telling Mullinix that his dog was in the car. Campbell was also holding a hamburger in his left hand and wearing an orange polo shirt with a pair of glasses tucked into the neck.

When Mullinix reached the car, Campbell asked if he could give Mullinix his wallet, and Mullinix said, “Not yet.” R. vol. 5, Ex. 2, at 1:04-1:06. Campbell asked Mullinix why he was on his property, and Mullinix said that someone called about seeing a burglary taking place. Campbell said that must have been his neighbor, whom he identified by name. Campbell also repeated that he lived at the residence and gave his full name. Mullinix said that he needed to “do [his] process” to verify that information. Id. at 1:25-1:27. In Campbell’s desire to prove his place of residence, he repeatedly dropped his hands, prompting Mullinix to tell him to keep his hands up and to take Campbell by the arm throughout a back-and-forth exchange that went on for about two minutes.

During this back-and-forth, Campbell repeated that this location was his home and confirmed that Mullinix’s body-worn camera was on. Mullinix repeated that if this was Campbell’s home, he’d check Campbell’s identification and “figure it out.” Id. at 2:21-2:23. Despite Mullinix’s repeated directions not to reach for things, Campbell retrieved his wallet from his back pocket and handed it to Mullinix. Mullinix asked if Campbell had any weapons on him, Campbell responded in the negative, and Mullinix asked if he could check. But Campbell’s only response was to say again that the property was his home and to ask about probable cause, a warrant, and the Fourth Amendment. Mullinix told Campbell that he had reasonable suspicion that a crime was being committed. Mullinix then attempted to look through Campbell’s wallet with one hand while continuing to hold Campbell’s arm with the other; he did not appear to find a driver’s license. At the same time, Campbell provided the address of the residence and began describing his neighbors. Mullinix then said to Campbell, “Let me put you in my car, and we’ll figure it out.” Id. at 3:26-3:28.

Over the next two minutes, Mullinix and Campbell walked to the patrol vehicle at the end of the driveway, during which time Campbell continued to talk over Mullinix and to ignore commands until they were given several times. For instance, Campbell again tried to reach for his pockets despite Mullinix’s repeated instructions not to reach for anything. Campbell then reiterated that his driver’s license was in his wallet, which Mullinix had left on the hood of Campbell’s car. Mullinix responded that after he put Campbell in the patrol vehicle, he would find the driver’s license, and if it matched the address at issue, Campbell would be free to go. Mullinix then told Campbell that the woman who lived at the residence had reported someone stealing things from the back porch, and Campbell replied that she was his wife, Teresa Cooper.

Before putting Campbell in the patrol vehicle, Mullinix frisked Campbell for weapons, and Campbell admitted he was armed. Mullinix took a gun from Campbell’s waistband and a knife from his back pocket. After putting Campbell in the patrol vehicle, Mullinix called Cooper, who said that Campbell was her ex-husband and was allowed to be at the residence.[ii]

Campbell was subsequently indicted under federal law for being a felon in possession of a firearm.  He filed a motion to suppress the gun arguing the frisk violated the Fourth Amendment because the officer lacked reasonable suspicion to detain and frisk him.  The district court denied the motion and Campbell was convicted.  He then appealed the denial of his motion to suppress to the Tenth Circuit Court of Appeals.

On appeal, Campbell did not dispute that the officer initially had reasonable suspicion to detain him.  Rather, Campbell argued that after he told the officer he lived at the residence and provided his wallet that he said contained his identification, the reasonable suspicion dissipated such that by the time of the frisk, there was no reasonable suspicion to further detain or frisk him.  As such, he argued that the evidence (gun) should have been suppressed by the district court.

The court of appeals, noting that the encounter between Officer Mullinix and Campbell was an investigative detention, examined the legal principles associated with this type of encounter.

Investigative Detention: Two-Part Inquiry

The court first stated that, in determining if an investigative detention is reasonable under the Fourth Amendment, they must conduct a two-part inquiry.

Part One: Did the officer have reasonable suspicion

 The court discussed the first part of the inquiry and stated

The first question is whether the officer has “reasonable suspicion that criminal activity may be occurring.” Id. To evaluate reasonable suspicion, we “look at the totality of the circumstances.” Id. “Reasonable suspicion requires ‘more than an inchoate and unparticularized suspicion or hunch’ but ‘considerably less than proof of wrongdoing by a preponderance of the evidence.'” Id. (quoting United States v. Sokolow, 490 U.S. 1, 7 (1989)). “As long as an officer has a particularized and objective basis for suspecting an individual may be involved in criminal activity, he [or she] may initiate an investigatory detention.” Id. (quoting United States v. Pettit, 785 F.3d 1374, 1379-80 (10th Cir. 2015)). And the officer may do so “even if it is more likely than not that the individual is not involved in any illegality”—that is, to have reasonable suspicion, an officer need not rule out the possibility of innocent conduct. Pettit, 785 F.3d at 1379-80 (quoting United States v. Johnson, 364 F.3d 1185, 1194 (10th Cir. 2004)).[iii]

Thus, the key points regarding reasonable suspicion of criminal activity are as follows:

  • Reasonable suspicion is based on the totality of the circumstances;
  • Reasonable suspicion requires more than hunch or unparticularized suspicion;
  • Reasonable suspicion must be based on particularized, or specific facts, related to the possible crime at issue;
  • Reasonable suspicion requires less proof than probable cause and considerably less than the preponderance of the evidence;
  • Reasonable suspicion does not require the officer to rule out possible innocent conduct; and
  • An officer may conduct a stop or detention if reasonable suspicion exists.

Part Two: Was the detention reasonably related in scope to the reason for the stop

 The court discussed part-two of the inquiry and stated

At the second step of the inquiry, investigatory detentions “must be ‘reasonably related in scope to the circumstances’ prompting the stop.” Young, 99 F.4th at 1143 (quoting Terry v. Ohio, 392 U.S. 1, 19-20 (1968)). This means that any “‘investigative detention must be temporary and last no longer than is necessary to effectuate’ the purpose of either dispelling or confirming the officer’s reasonable suspicion.” De La Cruz, 703 F.3d at 1197 (quoting United States v. White, 584 F.3d 935, 953 (10th Cir. 2009)). “Once reasonable suspicion has been dispelled, ‘even a very brief extension of the detention without consent or reasonable suspicion violates the Fourth Amendment.'” Id. (cleaned up) (quoting United States v. Burleson, 657 F.3d 1040, 1045 (10th Cir. 2011)).[iv]

The key points regarding the scope of the investigatory detention are as follows:

  • An investigatory detention must be reasonable “in scope to the circumstances prompting the stop”;
  • An investigatory detention must last no longer than necessary to confirm or dispel the officer’s reasonable suspicion of criminal activity; and
  • If reasonable suspicion is dispelled, the person must be immediately released from the investigative detention because continuing to detain the person after reasonable suspicion has dissipated violates the Fourth Amendment.

Regarding dissipation of reasonable suspicion, the court discussed United States v. Trestyn[v], in which the court held that, when an officer stopped a car for a tag violation, the officer should have observed, upon walking up to the vehicle, that the registration number was properly displayed; as such, upon walking up to the vehicle and seeing the tag, the officer’s reasonable suspicion clearly dissipated.

In contrast, the court also discussed Amundsen v. Jones[vi], in which the court held that when an officer stopped a car because it weaved between lanes, providing the officer with reasonable suspicion of drunk driving, the reasonable suspicion continued through all field sobriety evaluations even the evaluations did not provide additional evidence supporting the belief of drunk driving.  In other words, the reasonable suspicion was not “clearly refuted” during the sobriety evaluations.

Application of the Rules to the Facts of Campbell’s case

 While Campbell does not dispute the officer’s initial reasonable suspicion, he did argue that it was “questionable.”  The court of appeals examined the relevant facts and noted the following:  (1) A female called 911 and reported a black male and female stealing items from her back porch; (2) it was midnight in a poorly lit area; (3) Officer Mullinix arrived approximately one minute after the conclusion of the 911 call; and (4) upon arrival, Officer Mullinix observed a black male (Campbell) just “steps” away from the back of the complainant’s house, which was where the theft was alleged to have occurred.  The court of appeals held that these facts supported reasonable suspicion that Campbell was involved in criminal activity, which satisfied part-one of the inquiry to determine the reasonableness of the investigative detention.

The court next examined part-two of the inquiry to determine the reasonableness of the investigative detention, particularly whether the detention was reasonable in scope to the reason for the stop.  Campbell argued that the reasonable suspicion dissipated before Officer Mullinix frisked him and discovered the gun.  In support of his argument, Campbell noted that (1) he did not flee, (2) he did not appear to be a burglar, (3) he had his car parked in the driveway with his dog inside, (4) he repeatedly told the officer he lived at that location, and (5) he provided the officer his wallet and told him his address and names of his neighbors and the 911 caller.

Regarding his appearance and lack of flight, the court stated

[O]fficers “need not rule out the possibility of innocent conduct” when assessing reasonable suspicion. United States v. Arvizu, 534 U.S. 266, 277 (2002); see also Pettit, 785 F.3d at 1379-80. What’s more, he fails to consider the totality of the circumstances as viewed from the perspective of a reasonable officer, which include that Mullinix arrived at the home within one minute of a call from the homeowner and found Campbell a few steps from the back of the house, where the homeowner had reported a suspected burglary. Further, Campbell fit the homeowner’s description of the suspect, and Mullinix believed, based on the magazine he saw in Campbell’s waistband, that he was armed. Moreover, Campbell was uncooperative in responding to the officer’s directions.[vii]

Campbell argued that being argumentative and uncooperative actually supported his story that he was telling the officer the truth regarding living at that location and it did not indicate that he may be a burglar.  The court of appeals replied

But a reasonable officer could view an argumentative and uncooperative detainee who he reasonably believed was carrying a gun as worthy of continued suspicion, even if that lack of cooperation could also be consistent with innocence. See United States v. Briggs, 720 F.3d 1281, 1286 (10th Cir. 2013) (“[A] suspect’s evasive . . . movements are considered as part of the totality of the circumstances that may justify a detention.”).[viii]

The court of appeals also considered that district court found the officer’s testimony that he immediately saw a black magazine sticking out of Campbell’s waistband credible.  Campbell argued that this is not relevant to reasonable suspicion because the court has previously held that when a person is exercising his Second Amendment rights, the presence of a gun does not give rise to reasonable suspicion of criminal activity.[ix]  The court of appeals distinguished that case from Campbell’s case because the men with guns in the case cited by Campbell were not involved any criminal activity; they were simply seen in a parking lot, getting into a vehicle, while carrying guns.  In contrast Campbell was seen when Officer Mullinix had reasonable suspicion that he may be involved in a burglary and the gun could have been carried in furtherance of the burglary.

Campbell also argued that Officer Mullinix “had a duty to quickly confirm Campbell’s identity and address by immediately locating Campbell’s driver’s license or calling the 911 caller.”[x]  The court of appeals responded to this argument and stated

Campbell draws this argument from our observation in Trestyn that the officer approaching the vehicle “reasonably could have observed the registration number.” 646 F.3d at 743 (emphasis added). But we made this statement in the context of an officer conducting a simple traffic stop premised on a license-plate violation, and any reasonable officer in that situation would likely look first to the license plate at issue. Here, by contrast, Mullinix reasonably suspected that Campbell had just committed a burglary and that he was armed. So Mullinix was reasonably concerned for his own safety when Campbell ignored his directions, was argumentative, and attempted to reach for his pocket or to get into his car. Nothing in Trestyn required him to review Campbell’s driver’s license before securing him.[xi]

Thus, the court of appeals held that Officer Mullinix’s reasonable suspicion had not dissipated at the time of Campbell’s frisk, and as such, the court affirmed the denial of the motion to suppress.

Note:  Court holdings can vary significantly between jurisdictions.  As such, it is advisable to seek the advice of a local prosecutor or legal adviser regarding questions on specific cases.  This article is not intended to constitute legal advice on a specific case.

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2 The magazine in Campbell’s waistband is not visible in the video footage, but the district court found Mullinix’s testimony on this point to be credible, and Campbell does not dispute as much on appeal.

[i]No. 23-6186 (10th Cir. September 30, 2025)

[ii] Id. at 2-6

[iii] Id. at 8-9 (emphasis added)

[iv] Id. at 9 (emphasis added)

[v] 646 F.3d 1040, 1045 (10th Cir. 2011)

[vi] 533 F.3d 1192, 1200 (10th Cir. 2008)

[vii] Id. at 12-13

[viii] Id. at 13 (emphasis added)

[ix] Id. at 13-14 (see United States v. Daniels, 101 F.4th 770 (10th Cir. 2024)

[x] Id. at 15

[xi] Id.