In the 

United States Court of Appeals 

For the Seventh Circuit ____________________

Nos. 19‐2090 & 19‐2101

UNITED STATES OF AMERICA,

Plaintiff‐Appellee,

v.

JONATHAN EYMANN and GARY LYONS,

Defendants‐Appellants.

____________________

Appeals from the United States District Court for the

Central District of Illinois.

No. 3:15‐cr‐30021 — Sue E. Myerscough, Judge.

____________________

ARGUED JANUARY 22, 2020 — DECIDED JUNE 12, 2020

____________________

Before WOOD, Chief Judge, and SYKES and HAMILTON, Cir‐

cuit Judges.

WOOD, Chief Judge. Jonathan Eymann and his uncle, Gary

Lyons, were flying from California to Pennsylvania when they

stopped around midnight at a small public airport in Litch‐

field, Illinois. Suspecting drug trafficking, law enforcement

officers followed the pair to a nearby hotel and confronted

them in the hotel’s parking lot. The encounter ended in their
2 Nos. 19‐2090 & 19‐2101

arrests and the discovery of 65 pounds of marijuana in their

airplane.  

Asserting that the officers had violated the Fourth and

Fifth Amendments in a number of ways, Eymann and Lyons

filed a joint motion to suppress the evidence against them. Af‐

terthe district court denied the motion, Eymann conditionally

pleaded guilty to conspiracy to distribute marijuana, reserv‐

ing the right to appeal the district court’s ruling on their sup‐

pression motion. Lyons proceeded to trial, where a jury con‐

victed him of conspiracy to distribute marijuana and aiding

and abetting the possession of marijuana with the intent to

distribute. Both men now appeal the district court’s denial of

their motion to suppress. Finding no reason to set aside either

the district court’s factual findings or its ultimate conclusion,

we affirm.  

I

On July 20, 2013, Department of Homeland Security

(“DHS”) Special Agent Glen Harrington received a call and

an email from Agent Jeff Spencer of DHS’s Air and Marine

Operations Center (“AMOC”) about an airplane that would

be landing that night at the Litchfield Municipal Airport.

Spencer identified the plane as a single‐engine Cessna owned

by Elaine Pate and noted that the pilot would be Pate’s hus‐

band, Lyons. AMOC had been monitoring the Cessna for

months. Although it knew nothing inculpatory about the spe‐

cific plane, owner, and pilot, AMOC found the airplane’s

movement patterns and quick‐turn trips suspicious.

Spencer’s email, which included information collected by

AMOC research specialist Robert Keller, identified the air‐

plane by its tail number. The email also indicated that on the
Nos. 19‐2090 & 19‐2101 3

weekend of May 24, 2013, an unknown pilot flew the airplane

from California to Pennsylvania. The plane stayed in Pennsyl‐

vania for only about fifteen hours before returning to Califor‐

nia. Then, on the weekend of June 21, 2013, it again flew from

California to Pennsylvania and back; this time it remained in

Pennsylvania for only five hours. AMOC identified Lyons as

the pilot during the second trip.  

The email noted additional circumstances that Keller

found suspicious. In January 2013, the Cessna flew to Wat‐

sonville and Cloverdale, California, towns close to a known

marijuana smuggling hub. During the May and June 2013

trips, the plane had landed at small, rural airports late at night

to refuel when the airports were otherwise closed. Keller also

found it odd that the plane apparently had flown through a

serious storm during one of its cross‐country trips. Finally, he

reported that Lyons had been in some economic trouble and

had just emerged from bankruptcy in 2012.

After evaluating AMOC’s information, Harrington con‐

cluded that the pilot might be using the plane to smuggle

drugs. This was consistent with his experience: every time in

the past when Harrington had pursued a lead based on infor‐

mation provided by AMOC, it led to the seizure of illicit

drugs. Harrington relayed Spencer’s tip to his supervisor,

Resident Agent‐in‐Charge Michael Mitchell. Harrington then

called Lieutenant Lee Jarman of the Litchfield Police Depart‐

ment to coordinate assistance. Harrington and Jarman ar‐

ranged to have a trained drug‐detection dog available for use

that night. They believed that the Cessna would land, refuel,

and take off again, and Harrington wanted to get a sniff of the

plane while it was on the ground. Jarman contacted the
4 Nos. 19‐2090 & 19‐2101

department’s dog handler, Officer Shane Grammer, and in‐

structed him to be available.  

Harrington arrived in Litchfield at around 11:00 p.m. to

meet with his team at the police department. After a short

briefing, five of them (Mitchell, Harrington, Jarman, former

Chief B.J. Wilkinson, and Officer Thomas Melchert) headed to

the airport. The officers watched the area for about an hour;

during which no airplane landed, there were no vehicles en‐

tering or leaving the airport, and the lights were off inside the

airport’s main building.  

Lyons landed the Cessna at around 12:05 a.m. on July 21,

2013. It taxied behind the airport’s main building and then

parked in an open area. It did not enter a hangar and was not

tethered to the ground. Harrington watched as Eymann and

Lyons removed cargo from the airplane and entered the

building. After a few minutes, the pair left the building and

loaded cargo into the airport’s courtesy car. (Harrington tes‐

tified that he thought their cargo included a box, which he

found suspicious, but no box was found in the later search.

We thus disregard the alleged box.) The courtesy car operates

on an honor system. Users simply provide a driver’s license

number and a signature on a form next to the car keys in the

airport building’s lobby. Lyons signed out the keys, and the

duo left the airport in the courtesy car at around 12:27 a.m.  

As the two men drove off, Harrington was concerned that

they could be delivering contraband. He saw that possibility

as a “more immediate threat” than the parked airplane at the

airport. The officers therefore decided to follow the courtesy

car. After a short drive, they saw it pull into a Quality Inn

parking lot. Lyons, who was driving, parked in the last
Nos. 19‐2090 & 19‐2101 5

available space. The two then got out of the car and began

walking to the hotel; as they did so, they noticed the officers.  

Mitchell pulled into the lot as Lyons and Eymann were

parking. He positioned his truck behind the courtesy car, and

Harrington parked nearby. Wilkinson placed his vehicle in

front of the courtesy car, thereby effectively blocking the cour‐

tesy car from moving in any direction. At 12:32 a.m. Mitchell

activated his lights and got out of his truck.  

Mitchell walked over to Lyons, showed his credentials,

identified himself as a law enforcement officer, and asked to

speak with him. Lyons cooperated while Mitchell asked him

basic questions such as where he was traveling to and from

and the nature of his trip. Lyons replied that he was flying

from California to Pennsylvania for work. The exchange was

conversational, and Mitchell did not raise his voice.  

While Mitchell was speaking with Lyons, Harrington ap‐

proached and asked for Lyons’s identification. After receiving

it, he approached Eymann with the same request. Harrington

took both identification cards back to his vehicle to check for

outstanding warrants.  

Meanwhile, as Mitchell continued to speak with Lyons,

Lyons suddenly became flush and fainted, collapsing into

Mitchell. The officers placed him in the front passenger seat

of Wilkinson’s vehicle with the door open and the air condi‐

tioning on. They did not question him any further at that

point about anything other than his medical condition.  

While others saw to Lyons, Harrington discovered that

neither man had an active warrant. Harrington then ap‐

proached Eymann and asked him some questions about Ly‐

ons’s health. He also asked Eymann if he had brought any
6 Nos. 19‐2090 & 19‐2101

marijuana from California. Eymann admitted that he had a

small, personal‐use, amount of marijuana in the car.  

Eymann’s admission prompted an escalation in the en‐

counter. Jarman ordered Grammer and his drug‐dog Arie to

the scene at 12:33 a.m.; they arrived around 12:54 a.m. Gram‐

mer and Arie got to work right away, and shortly thereafter

Arie positively alerted at the front passenger door seam.

Grammer rewarded Arie with a towel to chew on, while the

officers opened the car, removed the items, and spaced them

out on the ground. (There was some dispute in the district

court about the sequence of events: did Arie’s alert come first

and then the search of the car, or vice versa? Eymann and Ly‐

ons have not pursued this on appeal, and so we do not need

to resolve the point.) Arie alerted on a piece of luggage, which

the officers then searched. Once again, Arie was rewarded.

The officers found a small amount of marijuana (about 2.5

grams) within the luggage.  

Around the time Arie was sniffing around the courtesy

car, Harrington frisked Lyons. During the frisk, Harrington

felt what he thought was a stack of money in Lyons’s front

cargo pocket. Harrington asked Lyons what was in his pocket,

and Lyons replied that he had $1,600 in an envelope for fuel

and expenses; the envelope actually contained $2,600. Arie

later sniffed the envelope and alerted.  

After the officers found the marijuana, they handcuffed

and arrested both Eymann and Lyons. They then transported

the pair back to the airport, which they entered through the

airport gate with the permission and assistance of airport

agents. The Cessna was still the only airplane on the tarmac,

and the airport still looked empty.  
Nos. 19‐2090 & 19‐2101 7

Grammer walked Arie around the Cessna for another

sniff, and Arie provided another positive alert, followed as be‐

fore by a reward. The officers opened the plane using a key

they had seized from Lyons, and they immediately smelled

marijuana. This time the quantity was considerable. The offic‐

ers placed several bags from inside the plane on the tarmac

and had Arie check each one. He alerted on three of them and

(following a now‐familiar pattern) received a reward. The of‐

ficers searched the bags and found a total of 65 pounds

(roughly 29.5 kilograms) of marijuana. In a later search of the

airplane, they also found a firearm.  

In July 2013, the Montgomery County State’s Attorney

charged Eymann and Lyons with possession of over 500

grams of marijuana. They filed a motion to suppress evidence,

arguing that Arie was not properly certified through the State

of Illinois at the time of the sniffs. Although Arie had com‐

pleted the necessary training to be certified by the state, his

certification had lapsed weeks before as a result of an admin‐

istrative error. After a hearing, the state court determined

that, because of Arie’s lapse in certification, Arie’s alerts did

not provide probable cause. It granted the defendants’ mo‐

tion, and the state later dismissed the charges.  

That proved to be just the end of the beginning, not the

beginning of the end, of Eymann and Lyons’s troubles. On

May 6, 2015, a federal grand jury returned an indictment

charging both of them with conspiracy to distribute mariju‐

ana, in violation of 21 U.S.C. §§ 846, 841(a)(1) and (b)(1)(D),

and aiding and abetting the possession of marijuana with the

intent to distribute, in violation of 21 U.S.C. §§ 841(a)(1),

(b)(1)(D), and 18 U.S.C. § 2. Lyons was also charged with
8 Nos. 19‐2090 & 19‐2101

carrying a firearm during and in relation to a drug trafficking

crime, in violation of 18 U.S.C. § 924(c)(1)(A)(i).

In October 2015, Lyons and Eymann filed a joint motion to

suppress evidence and a supporting memorandum; they al‐

leged multiple constitutional violations during their encoun‐

ter with law enforcement. The district court held a hearing on

the motion and, in October 2016, denied it. Two years later,

Eymann entered a conditional plea of guilty to conspiracy to

distribute marijuana, reserving the right to appeal the district

court’s suppression decision. Lyons proceeded to trial, and a

jury convicted him of conspiracy to distribute marijuana and

aiding and abetting the possession of marijuana with the in‐

tent to distribute; it acquitted him of the gun charge. The dis‐

trict court sentenced Eymann to 10 months’ imprisonment

and Lyons to concurrent sentences of 27 months on each

count.  

II

We review a district court’s denial of a motion to suppress

under a dual standard of review: we apply the clear error

standard to its factual determinations, with special deference

to its credibility determinations, United States v. Villalpando,

588 F.3d 1124, 1127 (7th Cir. 2009); but we take a de novo ap‐

proach to its conclusions of law. Id.

A

Eymann and Lyons first contend that all the evidence the

police collected must be suppressed because it all flowed from

the encounter in the Quality Inn parking lot, and that encoun‐

ter was, at a minimum, an impermissible Terry stop that was

not supported by reasonable suspicion. They also argue that
Nos. 19‐2090 & 19‐2101 9

even if the officers had reasonable suspicion to do something,

their actions exceeded the scope of a Terry stop.  

The Fourth Amendment protects persons from “unreason‐

able searches and seizures.” U.S. Const. amend. IV. Generally,

seizures are “reasonable” only when they are based on prob‐

able cause. Dunaway v. New York, 442 U.S. 200, 213 (1979). The

Supreme Court recognized an exception to the probable‐

cause rule in Terry v. Ohio, 392 U.S. 1 (1968). Under Terry, po‐

lice officers may briefly detain a person for investigatory pur‐

poses based on the less exacting standard of reasonable sus‐

picion that criminal activity is afoot. 392 U.S. at 21–22.

Terry does not, however, lift all restrictions on police ac‐

tion. Reasonable suspicion exists only when an officer can

point to “specific and articulable facts which, taken together

with rational inferences from those facts, reasonably warrant

that intrusion.” Id. at 21. In making reasonable‐suspicion de‐

terminations, we “look at the ‘totality of the circumstances’ of

each case to see whether the detaining officer has a ‘particu‐

larized and objective basis’ for suspecting legal wrongdoing.”

United States v. Arvizu, 534 U.S. 266, 273 (2002). Reasonable

suspicion requires more than an “inchoate and unparticular‐

ized suspicion or ‘hunch’” but “considerably less than pre‐

ponderance of the evidence.” Illinois v. Wardlow, 528 U.S. 119,

123–24 (2000). Ultimately, the determination of reasonable

suspicion “must be based on commonsense judgments and

inferences about human behavior.” Id. at 125.

Eymann and Lyons argue that the officers had nothing

more than a hunch when they stopped the two men in the ho‐

tel parking lot, but the record demonstrates otherwise. First,

the officers on the scene were aware of the suspicious details

of the plane’s and pilot’s flight history. Based on AMOC’s tip,
10 Nos. 19‐2090 & 19‐2101

the officers knew that at least twice, the plane had flown from

California to Pennsylvania and back and remained on the

ground for only a matter of hours before returning. Officers

also knew that Lyons was the pilot on at least one trip. Such

quick‐turn flights, although not necessarily illegal, may con‐

tribute to reasonable suspicion of criminal conduct. See, e.g.,

United States v. Sokolow, 490 U.S. 1, 9 (1989) (flying 20 hours

from Hawaii to Florida and staying only 48 hours in Florida

contributed to reasonable suspicion); United States v. Simpson,

609 F.3d 1140, 1151–52 (10th Cir. 2010) (driving from Ne‐

braska to spend only one night in Reno contributed to a find‐

ing of reasonable suspicion); United States v. Ehlebracht, 693

F.2d 333, 337 (5th Cir. 1982) (four hour and 30 minute stop

before returning after a long trip was suspicious).

In addition, during these quick‐turn flights, the plane of‐

ten landed at small, rural airports to refuel at hours when the

airports and airport buildings were effectively closed. Alt‐

hough such travel patterns are not illegal, they may contribute

to reasonable suspicion, given that they could assist in shield‐

ing criminal conduct from detection. United States v. Michel,

588 F.2d 986, 998 (5th Cir. 1979) (finding reasonable suspicion

in part because “small country airports [a]re often used by

marijuana smugglers to fly loads in afterthe airfields closed”).

This factor may cut both ways, however, because a pilot who

lands at a closed airport apparently must use a credit or debit

card to refuel from a self‐service gas pump. This leaves a pa‐

per trial that could be avoided by refueling at an open airport

where the pilot could pay with cash.

The district court also noted that the agents were aware

that the plane had flown to Watsonville and Cloverdale, Cal‐

ifornia—places where AMOC had previously found drug
Nos. 19‐2090 & 19‐2101 11

trafficking. Courts have held that flights to or from high drug

trafficking areas may properly contribute to reasonable suspi‐

cion. See United States v. Espinosa‐Alvarez, 839 F.2d 1201, 1206

(7th Cir. 1987); United States v. Palen, 793 F.2d 853, 857 (7th Cir.

1986). On the other hand, in this era of increasing legalization

of marijuana, coupled with widespread cultivation, we con‐

sider this only a small nudge in the direction of reasonable

suspicion.  

We do agree with the district court’s determination that

the airplane’s alleged travel through bad weather did not con‐

tribute to reasonable suspicion. In his email, Keller flagged

that the plane had flown through a storm. The radar image

that AMOC provided, however, did not show the plane flying

through bad weather. Instead, it showed the plane’s flight

path overIndiana and Illinois. Stormy weatheris visible in the

plane’s past route at the time the image was captured. That

picture is not evidence that the stormy weather existed when

the plane was in that spot; the storm clouds could have moved

into the route after the plane had flown by.  

Eymann and Lyons attack the evidence we have just sum‐

marized with the contention that the agents should not have

relied on any information provided by Keller. They argue that

this basis is no better than the one in Florida v. J.L., 529 U.S.

266 (2000), where the Supreme Court found that police lacked

reasonable suspicion for a Terry stop. Id. at 274. There, the of‐

ficers’ suspicion that the defendant was carrying a weapon

“arose not from any observations of their own but solely from

a call made from an unknown location by an unknown

caller.” Id. at 270. Also, the anonymous call concerning the de‐

fendant “provided no predictive information and therefore

left the police without means to test the informant’s
12 Nos. 19‐2090 & 19‐2101

knowledge or credibility.” Id. at 271. Eymann and Lyons em‐

phasize that Harrington had never dealt with Keller and thus

could not assess Keller’s reputation. In addition, they say,

whereas the J.L. defendant’s carrying of a firearm was a crime,

no one reported any crime by them. Keller reported only sus‐

picions about otherwise lawful activity.

But Keller and Spencer were far from anonymous inform‐

ants. They both worked for DHS’s Air and Marine Operations

Center, which is part of DHS’s Customs and Border Protec‐

tion section and which, according to its website, “uses sophis‐

ticated technology to detect, identify, track, and direct the in‐

terdiction of suspect aviation and maritime targets in the

Western Hemisphere.” See cbp.gov, Air and Marine Opera‐

tions Leadership and Organization. One of AMOC’s jobs is to

monitor airplane activity to reduce drug trafficking by air.

Spencer and Keller were both acting within the scope of their

official responsibilities when they passed along their infor‐

mation about the Cessna to Harrington. Also, a similar tip

from AMOC in the past had led to the seizure of illegal drugs.

Spencer gave Harrington specific details, and the Litchfield

team witnessed firsthand activity by Eymann and Lyons that

corroborated the tip. Finally, the possible lawfulness of a per‐

son’s actions does not defeat reasonable suspicion. See

Navarette v. California, 572 U.S. 393, 403 (2014).

The information that Harrington received from Keller (via

Spencer) also falls within the collective‐knowledge doctrine.

Under the collective‐knowledge doctrine, officers may carry

out a stop even if they do not have firsthand knowledge of the

facts amounting to reasonable suspicion. See United States v.

Harris, 585 F.3d 394, 400 (7th Cir. 2009). Instead, “where law

enforcement authorities are cooperating in an investigation,
Nos. 19‐2090 & 19‐2101 13

as here, the knowledge of one is presumed shared by all.” Il‐

linois v. Andreas, 463 U.S. 765, 771 n.5 (1983). Collective

knowledge also applies to information that an officer receives

from those with the “training, responsibility or authority to

make a determination of reasonable suspicion.” United States

v. Colon, 250 F.3d 130, 137 (2d Cir. 2001).  

Spencer was a law‐enforcement officer at AMOC. Harring‐

ton and the other DHS and LPD officers involved in the stop

were entitled to rely on Spencer’s information, including the

report he received from Keller. Keller, as an intelligence re‐

search specialist at AMOC, is responsible for detecting suspi‐

cious activity among airplanes and sharing that information

with the appropriate officer(s). Therefore, the information

Harrington received from Spencer, which included infor‐

mation from Keller, properly contributed to a finding that the

officers had reasonable suspicion to stop Eymann and Lyons

in the hotel parking lot.  

B

The next question is whether the parking‐lot encounter ex‐

ceeded the scope of a Terry stop. To be lawful, “a detention

must be limited in scope and executed through the least re‐

strictive means.” United States v. Ienco, 182 F.3d 517, 523 (7th

Cir. 1999). “A seizure becomes an arrest when a reasonable

person in the suspect’s position would have understood the

situation to constitute a restraint on freedom of movement of

the degree which the law associates with formal arrest.” Id.

(internal quotation marks omitted). “The line between a law‐

ful Terry stop and an unlawful arrest is not bright.” United

States v. Askew, 403 F.3d 496, 507 (7th Cir. 2005). “Several fac‐

tors are relevant in deciding whether a Terry stop has become

an arrest[,] including the officer’s intent in stopping the
14 Nos. 19‐2090 & 19‐2101

individual, whether there was a search, whether, or how

much, questioning occurred, whether there was a show of

force and whether the person stopped could be said to have

been taken into custody.” United States v. Rodriguez, 831 F.2d

162, 166 (7th Cir. 1987).  

Eymann and Lyons, with the support of our dissenting

colleague, argue that the encounter in the parking lot, before

they were handcuffed, was more akin to an arrest than the

limited detention permitted under Terry. They point to the fol‐

lowing factors: the encounter occurred at night; the agents did

not advise them that they were free to leave; the agents

parked their vehicles in a way that did not allow the courtesy

car to leave; two of the police vehicles activated emergency

lights; the agents stood close to the two men and blocked their

entrance to the hotel; several officers were present and their

weapons were visible; and the officers took the men’s identi‐

fication cards.  

The answer to the question whether they were under ar‐

rest depends significantly on the underlying facts. The district

court found that there was no arrest until the officers hand‐

cuffed the two after they found marijuana in Eymann’s bag.

The earlier show of force, it found, was minimal. Although

there were quite a few uniformed officers and police cars, and

some of the cars had flashing lights, the officers did not draw

any weapons or raise their voices. This level of force is nor‐

mally not associated with a formal arrest. See Askew, 403 F.3d

at 508−09 (surrounding suspect’s car to prevent him from

leaving did not convert stop into arrest). In addition, the of‐

ficers investigated their suspicions by questioning Eymann

and Lyons immediately. These actions aligned with the pur‐

pose of the investigatory stop, as officers are “permitted to ask
Nos. 19‐2090 & 19‐2101 15

questions to determine an individual’s identity and to obtain

information confirming an officer’s suspicions.” United States

v. Johnson, 680 F.3d 966, 974 (7th Cir. 2012), overruled on other

grounds by Fowler v. Butts, 829 F.3d 788 (7th Cir. 2016); see

Hiibel v. Sixth Judicial Dist. Court of Nevada, Humboldt Cnty, 542

U.S. 177, 187–88 (2004). The duration of the questioning was

also brief. The officers asked the pair about their travel plans

until Lyons experienced his medical episode. At that point,

the officers turned their focus to Eymann. Agent Harrington

asked Eymann whether he had brought any marijuana. The

tone, the district court found, was calm and conversational,

and the questioning did not indicate that either Eymann or

Lyons was under arrest at that point.  

Eymann and Lyons’s strongest argument is that the offic‐

ers themselves characterized the stop as an arrest at the state

suppression hearing. Worse, they say, Wilkinson’s and Jar‐

man’s testimony at the state suppression hearing in March

2014 actually conflicted with their testimony at the federal

suppression hearing in 2015 and 2016. Eymann and Lyons

emphasize that, at the state‐court suppression hearing, Wil‐

kinson unequivocally said that the defendants were “in cus‐

tody” when the police officers arrived at the Quality Inn park‐

ing lot, and his choice of that phrase amounts to an admission

that the stop was an arrest. At that point, they contend, the

officers lacked probable cause to make those arrests, and so

the arrests were illegal and the evidence gathered afterwards

must be suppressed.

We have taken a close look at both the state‐court and the

federal‐court records, however, and we are satisfied that they

are not in conflict. At both hearings, Wilkinson and Jarman

emphasized that Eymann and Lyons were “not free to leave”
16 Nos. 19‐2090 & 19‐2101

from the moment the officers arrived at the Quality Inn park‐

ing lot. In addition, at both hearings, Wilkinson equated “not

free to leave” with being in custody. Wilkinson’s use of the

word “custody” (which he uses at both hearings) appears to

be based on the fact that the defendants were not free to leave.

There is no reason to think that he was offering a legal opinion

about whether their situation qualified as “custody” under

the law. See Thompson v. Keohane, 516 U.S. 99, 112–13 (1995)

(ultimate question whether a person is “in custody” is a

mixed question of law and fact and receives plenary review).

We learn little from the fact that the defendants were not

free to leave, because that is also true in standard Terry stops.

That constraint signals only that the interaction was not

merely a consensual encounter. See United States v. Williams,

945 F.2d 192, 196 (7th Cir. 1991). Moreover, the question

whether a person is under arrest is an objective one, not one

that depends on the officers’ beliefs. Ienco, 182 F.3d at 523.  

Because the officers used little show‐of‐force, kept their

questioning within reasonable bounds, and acted consistently

with an investigatory detention, we conclude, as the district

court did, that a reasonable person would not have under‐

stood that his freedom was restrained to the degree associated

with a formal arrest during the period before the handcuffing.  

C

Eymann and Lyons next argue that the officers did not

have probable cause to search the car. Probable cause to

search a vehicle exists “if, given the totality of the circum‐

stances, there is a fair probability that contraband or evidence

of a crime will be found in a particular place.” United States v.

Scott, 516 F.3d 587, 589 (7th Cir. 2008) (internal quotation
Nos. 19‐2090 & 19‐2101 17

marks omitted). “Admissions of crime, like admissions

against proprietary interests, carry their own indicia of credi‐

bility—sufficient at least to support a finding of probable

cause to search.” United States v. Harris, 403 U.S. 573, 583

(1971). Once Eymann admitted to having marijuana in the car,

the officers had probable cause to search it, unless there is

some problem with the admission.

That is the route Eymann tries to take. He says that he was

under arrest before he made the admission and that he made

the statement only in response to Agent Harrington’s post‐ar‐

rest questioning. That taints the admission, he argues, be‐

cause he had not yet received his Miranda warnings, and so it

cannot be used to establish probable cause. One problem with

this argument is that, as the district court found, Eymann had

no privacy interest in the car and thus could not challenge its

search. We need not opine on that point. Eymann’s argument

works only if he was in custody while he was being ques‐

tioned, and we have concluded that he was not. His admission

therefore gave the officers probable cause to search the cour‐

tesy car.

D

Once the marijuana was found in Eymann’s luggage, the

officers had probable cause to arrest Eymann. We are left with

Lyons’s arguments about his frisk and arrest.  

We start with the frisk. “For a frisk to be lawful, it must be

based on reasonable suspicion that ‘criminal activity may be

afoot and that the persons with whom [the officer] is dealing

may be armed and presently dangerous.’” United States v.

Lopez, 907 F.3d 472, 485 (7th Cir. 2018) (quoting Terry, 392 U.S.

at 30). “[G]iven the ... burdensome intrusion of a frisk, such
18 Nos. 19‐2090 & 19‐2101

action should only be allowed when the officer can point to

articulable facts that would establish the separate and specific

condition that the detainee has a weapon or poses some dan‐

ger.” United States v. Williams, 731 F.3d 678, 686 (7th Cir. 2013).  

Lyons asserts that the officers had no reason to think he

was armed or dangerous. He emphasizes that mere suspicion

of drug trafficking is insufficient to justify a frisk. Lyons, how‐

ever, failed to raise this argument before the district court, and

so he may not raise it now for the first time on appeal. Puffer

v. Allstate Ins. Co., 675 F.3d 709, 718 (7th Cir. 2012). Although

the motion to suppress contained many arguments, an im‐

proper frisk was not one of them.

E1

We now turn to Lyons’s arrest. Lyons argues that the of‐

ficers did not have probable cause to arrest him after they

found Eymann’s marijuana. “Probable cause for an arrest ex‐

ists if an officer reasonably believes, in light of the facts and

circumstances within his knowledge at the time of the arrest,

that the suspect has committed, or is committing, an offense.”

Thompson v. Wagner, 319 F.3d 931, 934 (7th Cir. 2003), as

amended on denial of reh’g (Mar. 14, 2003). We must “exam‐

ine the events leading up to the arrest” and then determine

“whether these historical facts, viewed from the standpoint of

an objectively reasonable police officer, amount to” probable

cause. Maryland v. Pringle, 540 U.S. 366, 371 (2003).

1 Section II.E. represents the views of only Chief Judge Wood. As ex‐

plained in her concurrence, Judge Sykes concludes that the officers had

probable cause to arrest Lyons. Judge Hamilton dissents on grounds ex‐

plained in his separate opinion.
Nos. 19‐2090 & 19‐2101 19

The district court found that there was probable cause to

arrest Lyons because the officers knew that (1) he had been in

the car with both Eymann and Eymann’s marijuana, (2) he

had been carrying $2,600 in cash (and missed by a thousand

dollars how much he had, when he responded to the officer’s

question), (3) he unloaded a box from a plane that had been

involved in numerous quick‐turn trips and that often landed

at rural, closed airports, and (4) upon being confronted by law

enforcement, he experienced a fainting episode. The district

court also cited Pringle, 540 U.S. 366, noting that the Supreme

Court held that officers who found drugs in a car had proba‐

ble cause to arrest all three of the car’s passengers where the

drugs were accessible to all three men and all three failed to

offer information about the drugs’ ownership.  

Pringle is not very helpful, as it is easily distinguishable.

Whereas the suspects in Pringle refused to concede ownership

of the drugs, Eymann frankly admitted to his ownership of

his personal‐use marijuana. The officers had no reason to

doubt Eymann’s claim that the drugs were his, and the quan‐

tity did not lend itself to a shared‐ownership theory. The

other reasons the district court listed for finding probable

cause are also weak. Although Lyons experienced a fainting

spell, “[m]ost people, when confronted by a police officer, are

likely to act nervous, avoid eye contact, and even potentially

shift their bodies as if to move away from the area.” Williams,

731 F.3d at 687. And, as noted earlier, the question whether

there was a box at all is disputed, much less whether the ex‐

istence of a box on an airplane—one that did not make it into

the courtesy car—is anything but innocuous. For these rea‐

sons, Chief Judge Wood concludes that the officers did not

have probable cause to arrest Lyons.  
20 Nos. 19‐2090 & 19‐2101

F

Our focus, however, is on the evidence the police seized,

not the validity of the arrest for its own sake. Lyons and Ey‐

mann argue that Lyons’s unlawful arrest led to the search of

the Cessna, and so the evidence of the marijuana stash must

be suppressed. (As nothing turns on it, we assume for present

purposes that both had enough interest in the Cessna to com‐

plain about this search.) They note that when the officers ar‐

rested Lyons, they found and took the airplane’s keys, and

they used those keys to open the airplane during the search.

The pair compares these events to the events in United States

v. Ienco, 182 F.3d 517 (7th Cir. 1999). In Ienco, police arrested

two men without probable cause. Id. at 524−25. While the two

were unlawfully detained in the back of the police car, one

accidentally dropped the key to their van. Id. at 528. Hours

later, the police found the key and used it to gain access to the

van, where they found weapons. Id. at 522. Affirming the dis‐

trict court’s motion to suppress the weapons as evidence, we

held that “if the arrest was illegal, evidence obtained by the

discovery of the key hidden in the police car and the ensuing

discovery, impoundment, and search of the van would be in‐

admissible, all that being the fruit of the unlawful arrest.” Id.

at 526, 529.  

The government argues that even if the arrest was im‐

proper, the inevitable‐discovery doctrine applies, and on that

basis the evidence from the airplane should not be sup‐

pressed. Under the inevitable‐discovery doctrine, if the pros‐

ecution can establish by a preponderance of the evidence that

the challenged evidence ultimately would have been discov‐

ered through lawful means without regard to the constitu‐

tional error, then the evidence is not subject to suppression.
Nos. 19‐2090 & 19‐2101 21

United States v. Jones, 72 F.3d 1324, 1330 (7th Cir. 1995). To sat‐

isfy this burden the government must demonstrate (1) that “it

had, or would have obtained, an independent, legal justifica‐

tion for conducting a search that would have led to the dis‐

covery of the evidence,” and (2) that it “would have con‐

ducted a lawful search absent the challenged conduct.” United

States v. Marrocco, 578 F.3d 627, 637–38 (7th Cir. 2009). The

doctrine is premised on the idea that law enforcement

“should be placed in no better, but no worse, a position than

they would have been had no impropriety occurred.” Jones,

72 F.3d at 1330.

Although the district court did not reach inevitable dis‐

covery (because it found no constitutional errors), our conclu‐

sion with respect to Lyons’s arrest makes it necessary for us

to address this point. We may do so, because the parties de‐

veloped the necessary record in the district court.2 The first

question is whether the government had an independent, le‐

gal justification for conducting the search of the plane that led

to the discovery of the marijuana. We are satisfied that it did.

When the officers returned to the airport after the encounter

in the hotel parking lot, they entered the airport gate with the

permission and assistance of the airport agents. The officers

were therefore lawfully present on the runway. Moreover, the

officers were permitted to bring Arie to the plane and instruct

him to conduct an outdoor sniff test. Police officers need no

articulable reason to call in a drug‐sniffing dog as long as do‐

ing so does not otherwise invade a person’s legitimate interest

in privacy. See United States v. Jacobsen, 466 U.S. 109, 123 (1984)

2 The dissent believes that further development of this issue is needed

in the district court. Post at 12. With respect, we see no critical gaps in the

record that require filling.  
22 Nos. 19‐2090 & 19‐2101

(“[G]overnmental conduct that can reveal whether a sub‐

stance is cocaine, and no other arguably ‘private’ fact, com‐

promises no legitimate privacy interest.”); United States v.

Place, 462 U.S. 696, 707 (1983) (establishing that a dog’s sniff 

of luggage does not constitute a Fourth Amendment search).

Neither Lyons nor Eymann had a legitimate privacy interest

in the marijuana in the plane. Moreover, deploying Arie did

not invade Eymann’s or Lyons’s legitimate privacy interest

because the airplane was parked on an open runway. See

United States v. Grogg, 534 F.3d 807, 810–11 (7th Cir. 2008)

(“[T]he Supreme Court has made clear that a dog sniff in a

public place is not a search[,] because it is unique, in that it

does not intrude on or disclose any information other than

whether contraband is present, and a possessor of contraband

cannot maintain a legitimate expectation that the contra‐

band’s presence will not be revealed.”).  

If Arie’s alert on the airplane survives scrutiny, then it

gave the officers probable cause to search the plane independ‐

ent of anything that happened at the hotel. Lyons and Ey‐

mann contend that reliance on the dog’s alert was improper,

however, because Arie was uncertified at the time he sniffed

the airplane. They also claim Arie was unreliable. The record

establishes otherwise.

We should first say that the question whether Arie did or

did not have a particular state certificate is a question of state

law. The Fourth Amendment does not incorporate such state

requirements; it asks only whether, objectively, the officers

had probable cause to search. The record showed that Arie

successfully completed many training sessions. Starting in

2007, Arie completed a 10‐week program at the Illinois State

Police Canine Academy. He was trained to detect various
Nos. 19‐2090 & 19‐2101 23

drug odors and to refrain from alerting when odors otherthan

the specified set (proofing odors) were present. At the end of

the 10‐week program, Arie was tested and evaluated in 32 dif‐

ferent categories, and he received passing marks in each cate‐

gory. Afterthat program, Arie successfully completed a three‐ 

to five‐day refresher training at the Academy in 2008, 2009,

2010, 2011, and 2012. During each refresher course, Arie was

tested in at least 32 categories and passed in all evaluated ar‐

eas. The most recent refresher course Arie completed before

July 2013 was in November 2012, less than eight months be‐

fore the sniff. He earned a perfect score in 36 evaluated areas.  

Outside of the Academy, Grammer and Arie completed

bi‐weekly trainings with other handler/dog teams. Arie also

participated in additional out‐of‐state training programs. In

addition, during a July 2012 session, Arie received special

recognition for being the only dog successfully to pass a com‐

plex proofing odors test; the training included about 75 dif‐

ferent proofing odors and no drug odors, and Arie was the

only dog that went through the entire building without giving

a single false alert.  

Despite this record, Eymann and Lyons argue that Arie

was not reliable. They assert that Arie receives a reward every

time he alerts, even when no drugs are found, and so he is

motivated to alert during every drug sniff. In fact, the data

from 2012, they argue, shows that Arie performed 29 drug

sniffs and alerted positively to the presence of drugs in all of

them. In addition, they contend that even though Arie has

been trained to alert passively, the evidence shows that he

was aggressively alerting during the sniffs. These active

alerts, they insist, undermine the district court’s reliability

finding. Eymann and Lyons also emphasize that Arie was not
24 Nos. 19‐2090 & 19‐2101

properly certified during the sniffs. They note that even a

well‐trained dog is not permitted to search for drugs once its

certification expires.  

Taking the last point first, we reiterate that Arie’s lack of a

state certificate is not conclusive for federal constitutional

purposes. His lack of certification was attributable to an ad‐

ministrative error, not incompetence on the job. Once the er‐

ror was spotted, the state retroactively certified Arie for the

period that included the events in question. Even in the ab‐

sence of formal certification, “evidence of a dog’s satisfactory

performance in a certification or training program can itself

provide sufficient reason to trust his alert.” Florida v. Harris,

568 U.S. 237, 246 (2013). In addition, the 2012 data that Ey‐

mann and Lyons claim shows that Arie alerted positively

100% of the time was actually a record of only Arie’s positive

alerts, not of all of the drug sniffs he performed. Moreover,

Arie’s handler, Grammer, testified that Arie provided a pas‐

sive alert during the sniffs. Although Wilkinson testified that

Arie stopped, sat, and barked at the seam door, which the de‐

fendants argue is not a passive alert, the actions of stopping

and sitting are consistent with a passive alert. In addition,

Grammer was likely paying more attention to Arie’s actions

during the sniffs. We therefore agree with the district court

that at the time of his sniff of the plane, Arie’s alert could and

did establish probable cause.3  

3 The dissent queries whether the “automobile exception” to the

Fourth Amendment applies to a small airplane such as the Cessna. The

issue, we believe, is not properly before us, because the defendants did

not raise this point until their reply briefs. The dissent disagrees, asserting

that “the [automobile‐exception] question arose only in reply to the gov‐

ernment’s reliance on inevitable discovery as an alternate ground to
Nos. 19‐2090 & 19‐2101 25

This brings us to the second inquiry for inevitable discov‐

ery: the government must demonstrate that it would have

conducted a lawful search absent the challenged conduct. Ex‐

cept for Officer Wilkinson, the officers and agents are clear in

their testimony that they were going to bring Arie to the plane

to perform a sniff test regardless of what happened at the ho‐

tel. When asked if there was any circumstance where he

would not have called Grammer to walk Arie around the

plane, Jarman replied that he “would have ran [sic] that dog

no matter what [the agents] had decided” because he had pre‐

viously found drugs in a plane at the airport and did not want

the Litchfield Municipal Airport to be a stop for drug couriers.

Harrington testified that there were no circumstances under

which he would not have made use of a drug‐detection dog.

He also testified that even if the Litchfield Police Department

did not make Arie available, he “would have contacted Illi‐

nois State Police and arranged for one of their [dogs] to as‐

sist.” Mitchell testified that “regardless of how following that

car turned out,” “we would have definitely run the [dog]

around the plane.” Wilkinson’s testimony was more equivo‐

cal. He said that if the federal agents decided not to run the

affirm.” Post at 13 n.1. In their opening briefs, however, the defendants

argued that the search of the Cessna was unlawful because Arie’s alert

could not establish probable cause. We would reach the probable‐cause

question only if the automobile exception applied to the Cessna. The de‐

fendants therefore should have taken issue with the district court’s deter‐

mination that the automobile exception applied in their opening briefs.

We note as well that a number of circuits have found that the same ap‐

proach applies to airplanes. See, e.g., United States v. Linn, 30 F.3d 132, 1994

WL 399179, at *2 (4th Cir. 1994) (unpublished); United States v. Rollins, 699

F.2d 530, 534 (11th Cir. 1983); United States v. Gooch, 603 F.2d 122, 124 (10th

Cir. 1979). Because the issue has not been properly presented here, we do

not need to resolve this point.
26 Nos. 19‐2090 & 19‐2101

dog around the plane, he was not sure whether he would have

ordered Arie to be deployed. He “would have had to try to

validate why their suspicion was no longer valid or [why]

they didn’t want to pursue their suspicion, and then [he

would] have to make a decision.”

Wilkinson’s lack of certainty is not enough, in our view, to

overcome the testimony of all the other officers to the effect

that the airplane was the central focus of their interest. This

record shows that they would have walked Arie around the

plane even if they had not improperly arrested Lyons. Both

Eymann, whose arrest does pass muster, and Lyons were in

the plane, and all the other information suggesting that the

plane was being used for illegal drug operations was still

there. Wilkinson indicated that he would probably have de‐

ferred to the federal agents, and the federal agents testified

that they would have deployed Arie no matter what. Lyons’s

arrest was largely beside the point. The inevitable‐discovery

doctrine therefore applies, and the district court correctly re‐

fused to suppress the evidence found in the plane.  

G

Lastly, Lyons argues that the district court erred in finding

that the government was not collaterally estopped from liti‐

gating the suppression hearing in federal court. Recall that be‐

fore the federal charges were filed, the Montgomery County

Circuit Court found that Arie’s alerts on the courtesy car and

the plane could not establish probable cause because Arie was

not technically certified as a drug‐detection dog during those

sniffs. The state court determined that 50 ILCS 705/10.12 pre‐

cluded finding probable cause from an alert by an uncertified

dog. That finding prompted the state court to suppress the

evidence from the plane.  
Nos. 19‐2090 & 19‐2101 27

Collateral estoppel (or as we now say, issue preclusion) is

“properly applied when an issue raised by a party to a suit

has been actually and necessarily litigated in a prior suit and

when the party against whom estoppel is asserted has had a

‘full and fair opportunity’ to litigate the issue.” United States

v. Sherman, 912 F.2d 907, 909 (7th Cir. 1990). “The fourrequire‐

ments of collateral estoppel are that: (1) the issue sought to be

precluded is the same as that involved in the prior action; (2)

the issue was actually litigated; (3) the determination of the

issue was essential to the final judgment; and (4) the party

against whom estoppel is invoked was fully represented in

the prior action.” Id.  

Requirement 4 is not met here. Lyons argues that the state

suppression hearing provided the federal government a full

and fair opportunity to vindicate its rights, but the United

States was not a party to the state action or otherwise repre‐

sented in it. Issue preclusion “cannot apply here because it

holds only between the same parties, whereas the United

States was not represented in the prior case.” United States v.

Brocksmith, 991 F.2d 1363, 1367 (7th Cir. 1993). Although the

United States and Illinois worked together in the investiga‐

tion of the offense, joint law enforcement effort does not mean

the prosecuting entities are in privity for the purposes of issue

preclusion. United States v. Davis, 906 F.2d 829, 834 (2d Cir.

1990). The United States is not bound by the state court’s res‐

olution of the suppression issue.  

We therefore AFFIRM the district court’s denial of Eymann

and Lyons’s motion to suppress, and thus the judgments en‐

tered against both defendants.
28 Nos. 19‐2090 & 19‐2101

SYKES, Circuit Judge, concurring. I join Chief Judge

Wood’s opinion except for Part IIE, which concludes that

DHS Special Agent Harrington and his law‐enforcement

team lacked probable cause to arrest Lyons. In my view, the

officers had probable cause to arrest Lyons based on the

following facts known to them at the time:

 Lyons piloted at least one of the cross‐country, quick‐

turn Cessna flights from California that prompted the

call and email from DHS’s Air and Marine Operations

Center to Agent Harrington. That flight—on the

weekend of June 21, 2013—followed the same pattern

as the one just a few weeks before on the weekend of

May 24. During both trips, the plane landed at small,

rural airports late at night, when the airports were

otherwise closed, and used self‐service pumps to re‐

fuel.

 Lyons’s wife owned the plane.

 When Harrington frisked Lyons, he felt what he

thought was a wad of cash in his pocket. When asked

about it, Lyons said it was an envelope containing

$1,600. But the envelope actually contained $2,600 in

cash. Misstating the amount by $1,000 was suspicious.

 Lyons said the cash was for fuel and expenses, but

Harrington knew that the self‐service pumps at rural

airports do not take cash. This added to the suspicion.

 Lyons’s fainting spell: Nervousness may be common

in a police encounter, but fainting is unusual, as

Harrington testified. This goes beyond the garden‐

variety nervousness mentioned in United States v.

Williams, 731 F.3d 678, 687 (7th Cir. 2013).
Nos. 19‐2090 & 19‐2101 29

These facts—and the discovery of Eymann’s marijuana—

add up to probable cause. I agree, however, with Chief

Judge Wood’s analysis and application of the inevitable‐

discovery doctrine. So my disagreement on the probable‐

cause point means only that we end up in the same place for

two reasons.
30 Nos. 19‐2090 & 19‐2101

HAMILTON, Circuit Judge, dissenting. I agree with several

portions of the majority opinion, but I differ from the majority

on three decisive issues. First, the initial police tactics in the

hotel parking lot amounted to unjustified arrests without

probable cause, not merely an investigative stop. Second,

even if the parking lot encounter were only an investigative

Terry stop, the police lacked reasonable suspicion at the outset

even to stop Eymann and Lyons. Reasonable suspicion

should require more than the curiosity of law enforcement of‐

ficers. Third, the majority errs in deciding the fact‐intensive

issue of inevitable discovery, which the district court did not

reach. I would vacate both defendants’ convictions and re‐

mand for fact‐finding on the government’s affirmative de‐

fense of inevitable discovery. I respectfully dissent.

I. The Arrests in the Hotel Parking Lot

A reasonable person surrounded by the police in the hotel

parking lot that night would have understood that he was un‐

der arrest. In fact, the police officers testified in the state trial

court that Eymann and Lyons were under arrest from the mo‐

ment they were surrounded in the parking lot—at least one

officer explicitly, with the others confirming factual details in‐

dicating that the encounter was an arrest. Police Chief Wil‐

kinson testified:

Q. Was Mr. Eymann arrested at that point

[when the police cars pulled up behind their

vehicle]?

A. He was in custody, yes, sir.

In response to a question about “arrest,” that answer can‐

not plausibly be explained, as the majority opinion does, as

having meant “only a Terry stop.” A year later, though, the
Nos. 19‐2090 & 19‐2101 31

officers changed their testimony in the federal district court.

This time, they claimed the initial detention was only a Terry

stop. But these experienced police officers knew the difference

between an arrest and a Terry stop when they testified in state

court. They were right the first time.

The line between a Terry stop and an arrest is “not bright,”

United States v. Askew, 403 F.3d 496, 507 (7th Cir. 2005), but it

is exceedingly important. Terry recognized a “wholly differ‐

ent kind of intrusion upon individual freedom” based, for the

first time, on less than probable cause to believe the suspect

was engaged in crime. Terry v. Ohio, 392 U.S. 1, 26 (1968). If

courts allow law enforcement officers to cloak as “investiga‐

tory stops” what are really just arrests without probable

cause, all of us will have less liberty than the founders estab‐

lished for us in the Fourth Amendment.

The majority concludes that the parking lot encounter was

a Terry stop “[b]ecause the officers used little show‐of‐force,

kept their questioning within reasonable bounds, and acted

consistently with an investigatory detention,” such that “a

reasonable person would not have understood that his free‐

dom was restrained to the degree associated with a formal ar‐

rest during the period before the handcuffing.” Ante at 16.

I disagree. While there is no bright line between an arrest

and a Terry stop, “common sense and ordinary human expe‐

rience must govern.” United States v. Sharpe, 470 U.S. 675, 685

(1985). As many as nine officers in multiple marked cars

pulled in behind defendants’ car, blocking it in. At least two

cars were flashing their colored emergency lights. The armed

and uniformed officers, some in tactical gear and body armor,

then approached the defendants. A few moments later, an of‐

ficer took the defendants’ identification and did not return it.
32 Nos. 19‐2090 & 19‐2101

Eymann and Lyons were then separated before Eymann was

questioned. Chief Wilkinson confiscated the keys to the air‐

port courtesy car that the men had been driving. Common

sense and ordinary human experience should convince us

that this scene was not consistent with the notion of a brief

encounter “to ask you a few questions.”

These facts are sufficiently similar to those of United States

v. Ienco, 182 F.3d 517 (7th Cir. 1999), to show an arrest: a sig‐

nificant show of force, overwhelming police presence, and

identification and keys taken and kept by the police. See id. at

525, citing Florida v. Royer, 460 U.S. 491, 501–02 (1983) (where

officers at airport identified themselves as narcotics agents,

told defendant that he was suspected of transporting narcot‐

ics, and asked him to accompany them to a police room, while

retaining his airline ticket and driver’s license without indi‐

cating in any way that he was free to depart, defendant was

effectively seized for purposes of Fourth Amendment), United

States v. Gonzalez, 763 F.2d 1127, 1131–32 (10th Cir. 1985) (“ar‐

rest” found where police held driver’s license, car registration

and title), and United States v. Miller, 589 F.2d 1117, 1127 (1st

Cir. 1978) (police officer’s retention of the defendant’s driver’s

license which prevented the defendant from lawfully driving

his car was more of an arrest than a mere investigatory stop).

We have also held that large numbers of armed police tend to

indicate that a defendant was in custody. See, e.g., United

States v. Slaight, 620 F.3d 816, 820 (7th Cir. 2010); United States

v. Borostowski, 775 F.3d 851, 860–61 (7th Cir. 2014).

What happened here was distinct from the common police

practice of asking for and briefly inspecting identification

during a traffic stop, cf. Hiibel v. Sixth Judicial Dist. Court, 542

U.S. 177, 186 (2004), and United States v. Hensley, 469 U.S. 221,
Nos. 19‐2090 & 19‐2101 33

229 (1985). In such routine stops, most drivers expect to re‐

ceive their identification back within a few minutes. With no

driver’s licenses, and no expectation of getting them back any

time soon, and amid an overwhelming police presence, Ey‐

mann and Lyons were effectively under arrest from the out‐

set.  

Finally, I cannot overlook the testimony of Chief Wil‐

kinson in the state court hearing on the motion to suppress

(which was eventually granted, leading to this Plan‐B federal

prosecution). In the state court, the Chief testified that the en‐

counter with Eymann and Lyons in the hotel parking lot was

an arrest from the start. Chief Wilkinson is an experienced of‐

ficer who surely knew the difference between an arrest and a

Terry stop. In a hearing on the broad‐based motion to sup‐

press, he testified this was an arrest. (The Illinois State’s At‐

torney never even contested this point: he said in his closing

argument that “The state is not going to try and sit here and

argue that they weren’t in custody.”) I’m troubled by Chief

Wilkinson’s changed testimony on this critical point after the

prosecution lost the motion to suppress in state court. He was

right the first time.

The government does not claim, and could not claim, that

the officers had probable cause to arrest Eymann or Lyons in

the opening moments of the encounter in the parking lot. This

was an arrest without probable cause, and all of the evidence

obtained through the unlawful arrest should have been sup‐

pressed.

II. No Reasonable Suspicion to Detain

Even if the parking lot encounter were properly deemed

only an investigative Terry stop, it was unconstitutional. The
34 Nos. 19‐2090 & 19‐2101

officers had received information that they could reasonably

deem worth investigating. That information fell short, how‐

ever, of grounds to stop Eymann and Lyons at the hotel that

night and thus to deprive them of their liberty. The officers

needed “a reasonable suspicion, grounded in specific and ar‐

ticulable facts,” that the men had committed a felony or were

about to commit a crime. Hensley, 469 U.S. at 229; United States

v. Lopez, 907 F.3d 472, 478 (7th Cir. 2018). They did not have

it.

The Air and Marine Operations Center (AMOC) analyst

passed on to officers that a single‐engine Cessna was worth

investigating further because it had made prior quick‐turn

trips and used self‐service fuel pumps late at night. Although

the analyst said that these attributes were “similar to previous

violators,” the analyst also told the officers that “the plane,

owner, and pilot [were] nonsuspect.” (Like the majority, I

give little weight to the California origins of the flights or to

the mistaken impression that the plane had flown into bad

weather.) In short, the AMOC information did not set Ey‐

mann, Lyons, or their plane apart from the pool of law‐abid‐

ing pilots who make quick‐turn trips or use self‐service fuel

pumps at night.

It is critical to respect the difference between the quantum

of suspicion required to stop a suspect and what is required

merely to investigate. No more than interest or curiosity on the

part of the police is required to investigate. Neither is enough

to justify an investigative stop, intruding on a person’s liberty.  

To make a lawful stop, police “must be able to point to

specific and articulable facts which, taken together with ra‐

tional inferences from those facts, reasonably warrant that in‐
Nos. 19‐2090 & 19‐2101 35

trusion.” Terry, 392 U.S. at 21. Though law enforcement offic‐

ers are entitled to a certain amount of deference, courts must

still ensure that reasonable suspicion rests on an adequate ob‐

jective basis. See, e.g., id. at 21–22. Without an objective basis

giving rise to individualized suspicion, nothing sets apart

those reasonably suspected of criminal activity from those in‐

nocent Americans going about their daily lives—an outcome

that is inconsistent with the mandate of the Fourth Amend‐

ment. Kansas v. Glover, 140 S. Ct. 1183, 1190 (2020) (reasonable

suspicion does not “allow officers to stop drivers whose con‐

duct is no different from any other driver’s”); United States v.

Flores, 798 F.3d 645, 649 (7th Cir. 2015) (explaining that a “sus‐

picion so broad that [it] would permit the police to stop a sub‐

stantial portion of the lawfully driving public,” such as that

based on a license plate frame that obstructed a license plate

in exactly the same way as every other license plate frame,

was unreasonable).  

By definition, the grounds for a Terry stop can be less than

those required for probable cause. United States v. Arvizu, 534

U.S. 266, 274 (2002). But when the activity is much more likely

to be explained by innocent behavior than by criminal, the in‐

ference is weakened so that it cannot meet even the relatively

low standard for reasonable suspicion.  

Consistent with Glover, we have looked for a stronger con‐

nection between fact and inference than the officers had here.

In United States v. Paniagua‐Garcia, 813 F.3d 1013, 1014 (7th Cir.

2016), we held that a police officer’s observation that a driver

had his cell phone in hand with his head bent toward the

phone while driving was not enough to support reasonable

suspicion that he was breaking Indiana law by texting while

driving. The officer’s observations did nothing to separate the
36 Nos. 19‐2090 & 19‐2101

driver’s behavior from any of the many other lawful uses of a

cellphone while driving, all of which, except for texting, were

then legal under Indiana law. Id. (The statute, Ind. Code § 9‐

21‐8‐59, has since been amended effective July 1, 2020 to allow

only hands‐free use of cellphones while driving. See Pub. L.

100‐2020, § 3 (2020).)  

The government argues here that Eymann and Lyons fit

criteria for drug couriers. The problem is that the profile

criteria were so general and so likely to point to innocent

behavior that—without further investigation—it was not

possible to gauge the likelihood that a specific plane or person

was involved in criminal activity. AMOC itself told the

officers from the outset that “the plane, owner, and pilot

[were] nonsuspect.” Even the factors noted by the AMOC as

worthy of investigation were not probative of much. The

record sheds no light on how often “quick turnaround”

flights are evidence of crime. Private planes are expensive

items to leave idle, after all, and they make sense not just for

drug couriers but for anyone who does not want to be tied to

airline schedules and major airports. There are lots of lawful

reasons to fly from California to other parts of the country.

And using small, closed airports to refuel requires pilots to

leave a trail by paying for fuel with a credit card, and seems

to be common enough among law‐abiding pilots to support

the “courtesy car” practice allowing pilots to borrow cars on

the honor system.

What the government here has called “reasonable suspi‐

cion” for Terry purposes was only interest or bare suspicion

that simply was not enough to justify a coercive, non‐volun‐

tary stop. Paniagua‐Garcia, 813 F.3d at 1015. We were con‐

cerned in Paniagua‐Garcia by how remote the likelihood of
Nos. 19‐2090 & 19‐2101 37

criminal activity was. We compared the case of a driver drink‐

ing from a coffee cup. The coffee could be spiked with alcohol,

or the driver could be driving on an expired license. Id. With‐

out more specific grounds for individual suspicion, however,

those possibilities could not justify a stop.

American liberty requires us to enforce the difference be‐

tween grounds to investigate by non‐coercive means and rea‐

sonable suspicion to carry out a Terry stop. What judges and

lawyers blandly call “Terry stops” can be highly intrusive.

With the authority to stop comes the authority to require the

subject to submit to the stop, and to use reasonable force to

make him submit. United States v. Place, 462 U.S. 696, 702

(1983) (Terry implicitly acknowledged authority of police to

make forcible stop based on reasonable suspicion); Adams v.

Williams, 407 U.S. 143, 146 (1972) (upholding forcible stop

based on tip from reliable informant). Such situations can es‐

calate quickly to violence and even death. See, e.g., Tom v.

Voida, 963 F.2d 952, 954 (7th Cir. 1992) (attempt to make justi‐

fied Terry stop led to officer fatally shooting subject); Brown v.

City of Milwaukee, 288 F. Supp. 2d 962 (E.D. Wis. 2003) (Terry

stop based on mistaken identification resulted in permanent

injuries and pain).

Here, when the officers encountered Eymann and Lyons,

as in Paniagua‐Garcia, they had information indicating at most

that criminal conduct was possible. It’s not surprising that

some small planes are used to transport drugs, but the record

tells us nothing about how suspicious the behavior that

AMOC observed was.  By comparison, case law shows that

many drug couriers drive cars on long trips on interstate high‐

ways. That fact, without more, is not enough to justify a Terry
38 Nos. 19‐2090 & 19‐2101

stop on any car with out‐of‐state plates on an interstate high‐

way. Courts insist instead that stops of vehicles be based on

much more specific information, including violations of traf‐

fic laws.

The facts here contrast sharply with a case cited by the

government, United States v. Latorre, 893 F.3d 744, 748, 751

(10th Cir. 2018), which affirmed the denial of a motion to sup‐

press. The police in Latorre knew of the private plane’s unu‐

sual flight pattern, but they also knew the pilot had a history

of arrests for drug possession and distribution. Most signifi‐

cant, the pilot was flying without using the required identifi‐

cation transponder. There may be legitimate reasons for that

last point—perhaps the transponder has suddenly stopped

working – but it is certainly suspicious. The Tenth Circuit held

that the three factors together supported reasonable suspicion,

and the lack of transponder was the most compelling. See id.;

see also Royer, 460 U.S. at 502 (officers had reasonable suspi‐

cion for initial Terry stop where drug courier paid for ticket in

cash under an assumed name). In this case, by contrast,

AMOC cited no behavior that indicated a desire to avoid de‐

tection. In fact, the opposite was true. When Eymann and Ly‐

ons stopped to refuel, they paid with a credit card that rec‐

orded the transaction.  

The patience shown by Officer McFadden in Terry itself is

also instructive here. Two men on the street caught his eye.

Terry, 392 U.S. at 5. At first, he could not say why they raised

his suspicion, so he waited and watched. He saw them pace

past and peer into a store many times, an activity that looked

to him like casing the store for a robbery. The officer contin‐

ued to watch. He saw the two men have a brief conversation

with a third man, who then left. The two men then resumed
Nos. 19‐2090 & 19‐2101 39

their activity in front of the store. The officer still did not at‐

tempt to detain them. He continued to investigate without

seizing anyone. As the two men began walking away, he fol‐

lowed them. When they met up with the third man once

again, Officer McFadden finally stopped them and found con‐

cealed weapons. Id. at 7. Terry thus showed the development

of the officer’s reasonable suspicion, starting from a vague

hunch that two men on the street were up to no good, to fi‐

nally observing enough suspicious actions that stopping them

had become reasonable. It was critical that the officer took the

time to observe something objectively suspicious before initi‐

ating his stop.

As with the initial hunch in Terry, the officers who re‐

ceived AMOC’s information had enough reason to investi‐

gate, by watching. But unlike in Terry, the defendants here

demonstrated no behavior that was clearly suspicious. The

police here did not take the time to use the information from

AMOC to see if the subjects started behaving in unusual and

objectively suspicious ways. The officers here were much too

hasty. They moved in to detain Eymann and Lyons well be‐

fore they had grounds to set them apart from the general, law‐

abiding population. The officers violated the Fourth Amend‐

ment by detaining them.

I do not suggest that the officers could not take any action

on the basis of the information from AMOC. The alert from

AMOC was to be on the lookout. It gave the officers a basis to

investigate—to observe the subjects and even to talk with

them if they were willing—but without (yet) restraining their

liberty. See United States v. Williams, 731 F.3d 678, 693 (7th Cir.

2013) (Hamilton, J., concurring) (anonymous call that a group
40 Nos. 19‐2090 & 19‐2101

of men outside a bar were showing each other their guns jus‐

tified a police response to investigate, but not to detain any‐

one without more reason to suspect wrongdoing when state

law allowed open possession of firearms).

Stopping pilots and passengers based on only the infor‐

mation relied on here would allow the police to detain a sub‐

stantial portion of those flying lawfully. The information pro‐

vided by AMOC gave the officers reason to investigate fur‐

ther, but it fell short of providing the reasonable suspicion

necessary to restrain anyone’s movements. The entire case

against Eymann and Lyons was built on that flawed founda‐

tion.

III. Inevitable Discovery?

The government argues that even if the arrest or stop was

unlawful, the evidence seized from the plane should be ad‐

mitted under the inevitable discovery doctrine. That doctrine

allows the government to rescue the fruits of an unlawful

search or seizure by showing, by a preponderance of the evi‐

dence, that the evidence would have been discovered through

lawful means independent from any illegal search or seizure.

United States v. Jones, 72 F.3d 1324, 1330 (7th Cir. 1995).

The wording is important: would have been discovered, as

events actually unfolded, not hypothetically might have been

discovered under a different and idealized set of circum‐

stances. The government needs to show either that it would

have obtained a warrant or that it would have been able to act

under a valid exception to the warrant requirement. The dis‐

trict court did not decide or make findings of fact on the inev‐

itable discovery theory.
Nos. 19‐2090 & 19‐2101 41

The majority forges ahead and makes its own factual find‐

ings on this fact‐sensitive issue. With respect, that’s a mistake.

First, inevitable discovery always asks for some degree of

counterfactual speculation. The government’s brief offers sev‐

eral hypotheticals as to how a dog might have been deployed

lawfully to sniff the plane, even absent the invalid arrest/Terry

stop and the defendants’ ensuing admissions. That argument

falls short of showing that a dog inevitably would have been

deployed to the plane. In fact, Chief Wilkinson conceded as

much when he said in the federal suppression hearing that he

would not have automatically deployed a drug‐sniffing dog

to the plane. Other officers testified differently, but this is not

a record where an appellate court should be making its own

findings of fact in the first instance.

Second, in this case there are legitimate questions about

the use of this dog, his training, and his reliability. The state

courts have already found that the dog was not properly cer‐

tified at the time of these events. How does that affect the in‐

evitability of lawful discovery? Third, it is not clearthat a war‐

rantless search of an airplane is subject to the same rules as a

warrantless search of an automobile.

It is possible that officers could have called a judge in the

middle of the night to obtain a warrant after a positive alert

from a reliable drug‐sniffing dog, and it is true that warrants

are often granted on this basis. It is not at all clear on this rec‐

ord that the officers would have actually done so. The scene

suggests that officers had no real plan. Upon seeing Eymann

and Lyons leave the airport, a federal agent made a spur‐of‐

the‐moment decision to follow them in their courtesy car. All

of the agents and officers then left the airport, leaving the

plane unattended. Given the number of agents and officers
42 Nos. 19‐2090 & 19‐2101

who converged on the hotel parking lot, surely one or two

could have been assigned to a dog sniff of the plane if that

really had been a foregone conclusion. Instead, when the dog

was actually deployed, it was first sent to the hotel parking

lot, not the plane. Given how events actually unfolded, the

government must hypothesize that the officers would have:

(1) deployed a drug dog to the plane, (2) executed a proper

sniff, (3) gotten a reliable positive hit, (4) applied  for a war‐

rant, and (5) waited for a warrant. There are too many uncer‐

tainties here for us to say confidently, at least without factual

findings, that the government can satisfy the strict require‐

ments of the inevitable discovery defense for an unlawful

search.

The government also argues that a warrant would not

have been necessary because the automobile exception to the

warrant requirement would have covered a hypothetical

search of the plane based on a positive dog alert.1

The automobile exception has a practical purpose: to allow

officers to search a car under the “exigent circumstances” in

which the vehicle is readily mobile. United States v. Castaldi,

1 Footnote 3 of the majority opinion criticizes the defendants for not

raising the automobile exception question until their reply briefs. On ap‐

peal, however, the question arose only in reply to the government’s reli‐

ance on inevitable discovery as an alternate ground to affirm. The district

court did not reach the inevitable discovery question, so defendants did

not need to address it in their principal briefs on appeal. It is now clear,

however, that affirmance of at least Lyons’s conviction depends on the in‐

evitable discovery theory. The majority’s point about limited briefing of

the issue thus only underscores the value of having the district court ad‐

dress this fact‐intensive question in the first instance. The only court to

have considered the issue until now, the Illinois trial court, rejected the

inevitable discovery theory for the search of the airplane.
Nos. 19‐2090 & 19‐2101 43

453 F.2d 506, 510 (7th Cir. 1971). Under that logic, the automo‐

bile exception has been extended to other kinds of vehicles

that are easy to drive away. See, e.g., California v. Carney, 471

U.S. 386, 393 (1985) (motor homes); United States v. Smith, 456

F. App’x 200, 209 (4th Cir. 2011) (travel trailer); United States

v. Navas, 597 F.3d 492, 501 (2d Cir. 2010) (tractor trailer).

This plane was not necessarily so mobile as to have made

seeking a warrant impractical. The plane was locked, the of‐

ficers had its key, and it was located in a different place than

Eymann and Lyons at the time of their arrests. Moreover, an

airplane cannot be moved as quickly and easily as an automo‐

bile. General aviation airports are not as public as open road‐

ways. Planes cannot easily be lost in a stream of traffic, and

flights can be tracked. Refueling a plane is not as simple as

stopping a car at the next highway exit. It could not be easily

stolen or broken into, and it did not offer a ready means of

escape. In short, this plane was going nowhere without the

officers’ express direction.

The automobile exception has also been justified by the di‐

minished expectation of privacy in an automobile. See, e.g.,

United States v. Matthews, 32 F.3d 294, 299 (7th Cir. 1994);

United States v. Markling, 7 F.3d 1309, 1319 (7th Cir. 1993) (au‐

tomobile exception applied to a car in a motel parking lot be‐

cause “[t]he considerations underlying the automobile excep‐

tion,” namely, the car’s ready mobility and the driver’s re‐

duced expectation of privacy, were present). Though air‐

planes and airways are also regulated, a private airplane may

offer much more privacy. An automobile is visible to the gen‐

eral public and any passerby. It has windows and a wind‐

shield that allow easy viewing of its driver, passengers, and

contents. The interior of a private plane in flight is not at all
44 Nos. 19‐2090 & 19‐2101

visible to the general public or even to people in other planes.

Planes are not subject to being pulled over the way that auto‐

mobiles are. There is little reason for pilots and passengers on

private planes to think that law enforcement or the general

public could easily access or see into their plane.  

I would not reach a conclusion on the government’s inev‐

itable discovery defense. The better course here would be to

remand these cases to the district court for factual findings in

the first instance, including thorough explorations of the

dog’s availability and reliability and whether the police could

have lawfully searched the airplane without a warrant.