BOYCE F. MARTIN, JR., Circuit Judge.
The United States of America appeals the district court's grant of William Edward Richardson's motion to suppress evidence seized from a vehicle in which he was a passenger. In light of the specific facts of this case and for the reasons that follow, we AFFIRM.
I
On October 19, 2000, Officer Darryl Fisher noticed a vehicle recklessly swerving between two eighteen-wheel trucks on Interstate 65 in Tennessee. Officer Fisher pulled the vehicle over for following too closely in violation of section 55-8-124 of the Tennessee Code. The entire traffic stop was recorded by the video camera in Officer Fisher's police car.
The following people were traveling in the vehicle: the driver, Ricky Collier; the defendant, Richardson; Richardson's wife, Shirley Richardson; and their son, William Darnell Richardson, whom we refer to as Darnell. Officer Fisher requested to inspect Collier's license. At this point, Officer Fisher noticed that the occupants of the vehicle appeared nervous. In particular, he noticed that Collier's hand trembled as he presented his license and Darnell's lips quivered as he spoke. Upon learning that Shirley Richardson was the owner of the vehicle, Officer Fisher requested to inspect her driver's license and registration. As she searched for this information, Shirley spilled all of the contents of her purse onto the floorboard. Officer Fisher perceived this action as a sign of nervousness. He asked the vehicle's occupants about their travel plans, to which Darnell responded that they had been to Nashville to see his lawyer. The videotape's sound recording reveals that Darnell also muttered something about having a back problem.
Officer Fisher then asked Collier to step to the back of the car. There, Officer Fisher informed Collier that he was going to issue a warning citation for traveling too closely to the first truck. Collier remained behind the car while Officer Fisher returned to his police car, where he narrated his impressions of the incident into the video camera, specifically noting the nervous appearance of the vehicle's occupants.
When Officer Fisher returned, he asked Collier about his travel plans. Collier responded that they had gone to Nashville to see a doctor. Officer Fisher then gave the citation to Collier and shook his hand, and Collier turned around to return to his vehicle.
At that point, Officer Fisher asked Collier to answer a few more questions, and Collier agreed. Officer Fisher asked whether there were any drugs, money, or guns in the car, to which Collier responded in the negative. Then, instead of allowing Collier to return to the vehicle, Officer Fisher asked Collier to remain behind the car while he asked Shirley Richardson for permission to search the car.
There is some dispute over the precise language that Officer Fisher used to indicate that he desired Collier to remain behind the car. The United States asserts that the district court erred as a factual matter in finding that Officer Fisher told Collier to "wait where he was" and instead asserts that Officer Fisher stated, "Okay, just hang out right here for me, okay?" This dispute, however, is not significant to our analysis and conclusion.
While Officer Fisher and Collier were talking, Darnell moved to the driver's seat. Thus, when Officer Fisher returned to the driver's side of the car, he asked Darnell for his driver's license. Darnell complied and Officer Fisher was satisfied with his identification. Officer Fisher then asked Darnell whether there were any guns in the car. Darnell responded that he had a gun in the vehicle. Darnell explained that his employer, the Lawrence County Sheriff's Department, authorized him to carry the gun. Darnell gave permission to Officer Fisher to inspect the gun. Upon inspection, Officer Fisher discovered that the gun was loaded. He stated that he would have to inquire into Darnell's employment and permit to carry the gun. Before doing so, however, Officer Fisher asked for permission to search the vehicle. The parties dispute whether Shirley Richardson gave her consent at this time.
Officer Fisher then radioed for assistance and also contacted the Lawrence County Dispatch to inquire about Darnell's employment. The dispatcher erroneously informed him that Darnell was not employed there and had been arrested a few times for drug possession. At this point, Officer Tommy Goetz arrived on the scene to assist.
Officer Fisher asked the occupants to exit the vehicle and empty their pockets. Defendant Richardson stated that his pants were too tight to empty his pockets. Officer Fisher patted down Richardson and noticed that Richardson turned his body to the left. Officer Fisher felt something on Richardson's left side. He proceeded to ask Shirley Richardson again whether he could search the vehicle and she responded in the affirmative. After Officer Fisher told Officer Goetz that he had felt something on defendant Richardson's left side, Officer Goetz conducted a second pat-down and discovered a handgun in Richardson's pocket.
Richardson was placed under arrest and subsequently indicted for possession of a firearm by a convicted felon in violation 18 U.S.C. §§ 922(g)(1) and 924(a). He moved to suppress the handgun evidence as fruit of an unlawful seizure. The district court granted the motion to suppress, holding that Officer Fisher seized the vehicle and its occupants for no reasonable suspicion. The United States filed this timely appeal.
II
In reviewing the judgment, we are asked to decide two questions: 1) whether the vehicle and its occupants were unlawfully seized following the conclusion of the traffic stop, and 2) whether the handgun evidence found thereafter was fruit of the unlawful seizure. We review the district court's factual findings in a suppression hearing for clear error and the district court's conclusions of law de novo. United States v. Waldon, 206 F.3d 597, 602 (6th Cir.), cert. denied, 531 U.S. 881, 121 S.Ct. 193, 148 L.Ed.2d 134 (2000); United States v. Guimond, 116 F.3d 166, 169 (6th Cir. 1997), cert. denied, 530 U.S. 1268, 120 S.Ct. 2733, 147 L.Ed.2d 995 (2000); United States v. Bradshaw, 102 F.3d 204, 209 (6th Cir. 1996). Also, because we are reviewing the grant of a motion to suppress, we review the evidence "in the light most likely to support the district court's decision." Guimond, 116 F.3d at 169 (quoting United States v. Roark, 36 F.3d 14, 16 (6th Cir. 1994)).
A. Seizure of the vehicle and its occupants
The primary interests that the Fourth Amendment protects include an interest in freedom of movement and insulation from the fear and anxiety produced by unlawful seizure. In the traffic stop scenario, these interests are personal to all occupants of the vehicle that is detained, United States v. Mesa, 62 F.3d 159 (6th Cir. 1995), because the detention affects an occupant's interest in freedom from such seizures. See Michigan Dep't of State Police v. Sitz, 496 U.S. 444, 450, 110 S.Ct. 2481, 110 L.Ed.2d 412 (1990) (recognizing that a passenger may challenge his detention because all occupants of a stopped vehicle are subject to a Fourth Amendment seizure); see also Delaware v. Prouse, 440 U.S. 648, 653, 99 S.Ct. 1391, 59 L.Ed.2d 660 (1979) (noting that each occupant has an interest in freedom from random, unauthorized, investigatory seizures); United States v. Kimball, 25 F.3d 1, 5 (1st Cir. 1994) ("interest in freedom of movement and the interest in being free from fear and surprise are personal to all occupants of a vehicle").
Unlawful seizure occurs when an officer, without reasonable suspicion, "by means of physical force or show of authority . . . in some way restrain[s] the liberty of a citizen." Terry v. Ohio, 392 U.S. 1, 19 n. 16, 88 S.Ct. 1868, 20 L.Ed.2d 889 (1968). One's liberty is restrained when a reasonable person would not feel free to walk away and ignore the officer's requests. United States v. Mendenhall, 446 U.S. 544, 554, 100 S.Ct. 1870, 64 L.Ed.2d 497 (1980). In United States v. Hill, 195 F.3d 258, 264 (6th Cir. 1999), cert. denied, 528 U.S. 1176, 120 S.Ct. 1207, 145 L.Ed.2d 1110 (2000), this Court determined that "[o]nce the purposes of the traffic stop [are] completed, a motorist cannot be further detained unless something that occurred during the stop caused the officer to have a reasonable, articulable suspicion that criminal activity was afoot." See also United States v. Mesa, 62 F.3d 159, 162 (6th Cir. 1995) ("Once the purposes of the initial traffic stop were completed, there is no doubt that the officer could not further detain the vehicle or its occupants unless something that occurred during the traffic stop generated the necessary reasonable suspicion to justify a further detention."). Thus, in determining whether the Fourth Amendment forbids the action taken by Officer Fisher in this case, we must decide whether there was a seizure, and, if so, whether Officer Fisher had reasonable suspicion for effecting the seizure.
In determining whether a particular encounter between an officer and a citizen constitutes a seizure, we recognize that words alone may be enough to make a reasonable person feel that he would not be free to leave. See United States v. Buchanon, 72 F.3d 1217, 1223 (6th Cir. 1995) (quoting Mendenhall, 446 U.S. at 554, 100 S.Ct. 1870). In the instant case, the traffic stop concluded when Officer Fisher handed Collier the citation and shook his hand. Collier was then free to leave, until Officer Fisher asked him to remain behind the vehicle. The United States makes much of the fact that Officer Fisher did not display an intimidating demeanor or use coercive language, but rather said, "Okay, just hang out right here for me, okay?" Regardless of Officer Fisher's demeanor, however, his words alone were enough to make a reasonable person in Collier's shoes feel that he would not be free to walk away and ignore Officer Fisher's request. When the driver is not free to leave, neither are his passengers; indeed, the passengers are at the mercy of any police officer who is withholding the return of their driver. See Sitz, 496 U.S. at 450, 110 S.Ct. 2481; Prouse, 440 U.S. at 653, 99 S.Ct. 1391; Kimball, 25 F.3d at 5. Thus, defendant Richardson's freedom of movement was subject to the will of Officer Fisher for as long as Officer Fisher detained Collier behind the car.
The United States argues that while the occupants may not have wanted to leave the scene, that "says nothing about whether Officer Fisher's conduct toward them was coercive." However, so long as Collier obeyed Officer Fisher's instruction to remain outside of the vehicle, his passengers were as unable as he to leave the scene. Also, that Darnell moved from his original position to the driver's seat does not affect our conclusion. This movement by itself indicates nothing about his willingness to drive away without Collier or his belief that he could lawfully take such action.
B. Reasonable suspicion
Having concluded that a seizure occurred, we now address whether Officer Fisher had the requisite reasonable suspicion to seize Collier and his passengers. In doing so, we must determine from the totality of the circumstances whether the seizure was supported by "`specific and articulable facts that give rise to a reasonable suspicion of criminal activity.'" United States v. Orsolini, 300 F.3d 724, 728 (6th Cir. 2002) (quoting United States v. Palomino, 100 F.3d 446, 449 (6th Cir. 1996)). At the outset, we recognize that "[r]easonable suspicion is more than an ill-defined hunch; it must be based upon a particularized and objective basis for suspecting the particular person . . . of criminal activity." United States v. Cortez, 449 U.S. 411, 417-18, 101 S.Ct. 690, 66 L.Ed.2d 621 (1981). We view the evidence offered in support of reasonable suspicion using a common sense approach, as understood by those in the field of law enforcement. Id.
In support of its argument that reasonable suspicion justified the seizure, the government combines the following factors:
(1)Nervousness, as evidenced by Collier's trembling hand, Darnell Richardson's quivering lip and difficulty speaking, and Shirley Richardson's spilling of the contents of her purse;
(2)Allegedly conflicting explanations of their travel plans; and
(3) Darnell Richardson's movement to the driver's seat.
The district court concluded that there was nothing inherently suspicious about the group's nervousness in this instance. We agree, and note that although nervousness has been considered in finding reasonable suspicion in conjunction with other factors, Mesa, 62 F.3d at 162, it is an unreliable indicator, especially in the context of a traffic stop, United States v. Saperstein, 723 F.2d 1221, 1228 (6th Cir. 1983). Many citizens become nervous during a traffic stop, even when they have nothing to hide or fear. Also, the allegedly conflicting explanations of their travel plans are not mutually exclusive; it is entirely plausible that the group traveled both to see a doctor and a lawyer. Finally, even Officer Fisher stated that he was not concerned that Darnell Richardson moved to the driver's seat, and the United States has made no attempt to explain why such behavior would be suspicious. Indeed, there are innocent and plausible explanations for this behavior — e.g., perhaps Darnell thought that Collier, after driving recklessly, needed to take a break from driving.
The United States argues that the district court erred by considering each factor individually and that when considering the factors in combination, reasonable suspicion existed to further detain Collier and his passengers. We recognize that even a string of innocent behavior added together may amount to reasonable suspicion of criminal activity. See United States v. Arvizu, 534 U.S. 266, 273-75, 122 S.Ct. 744, 151 L.Ed.2d 740 (2002). Yet, regardless of whether the district court improperly analyzed each factor individually, our independent review leads us to conclude that reasonable suspicion did not exist. See United States v. Smith, 263 F.3d 571, 591, 594 (6th Cir. 2001) (concluding, over the government's objection that the district court erred in analyzing each suspicious factor individually, that "[e]ven considering all of the government's proffered factors as a whole, we must conclude that [the] Officer . . . did not possess a reasonable, articulable suspicion that criminal activity was afoot"). Under the totality of the circumstances, the factors upon which the United States relies do not add up to a reasonable suspicion of criminal activity. Although "there is always a temptation in cases of this nature when . . . firearms are found to let the end justify the means," we must resist such temptation. Mesa, 62 F.3d at 163.
III
Absent reasonable suspicion, the evidence obtained as a result of the unlawful detention in this case must be suppressed as fruit of the unlawful seizure. There is, however, an exception to the rule when the causal chain is broken by a voluntary statement. United States v. Brown, 422 U.S. 590, 95 S.Ct. 2254, 45 L.Ed.2d 416 (1975); United States v. Arias, 344 F.3d 623 (6th Cir. 2003). The United States argues that even assuming that defendant Richardson was unlawfully seized, Darnell Richardson's voluntary, intervening admission that he was carrying a gun broke the causal chain between their illegal detention and the discovery that defendant Richardson carried a gun, thereby purging the original taint of the unlawful seizure.
We shall, in our discretion, decline to address this argument because, as the United States conceded, it did not raise the argument before the district court. See Singleton v. Wulff, 428 U.S. 106, 120-21, 96 S.Ct. 2868, 49 L.Ed.2d 826 (1976) ("The matter of what questions may be taken up and resolved for the first time on appeal is one left primarily to the discretion of the courts of appeals, to be exercised on the facts of individual cases."). Indeed, courts of appeals generally should decline to consider arguments that were not raised below and were not passed on by the district court. Hormel v. Helvering, 312 U.S. 552, 556, 61 S.Ct. 719, 85 L.Ed. 1037 (1941).
IV
For the foregoing reasons, we affirm the judgment of the district court.