                               In the

    United States Court of Appeals
                 For the Seventh Circuit
                     ____________________
No. 19-2054
UNITED STATES OF AMERICA,
                                                   Plaintiff-Appellee,
                                 v.

TERRILL A. RICKMON, SR.,
                                               Defendant-Appellant.
                     ____________________

         Appeal from the United States District Court for the
                     Central District of Illinois.
         No. 18-cr-10046 — James E. Shadid, District Judge.
                     ____________________

   ARGUED FEBRUARY 19, 2020 — DECIDED MARCH 11, 2020
                ____________________

   Before WOOD, Chief Judge, and FLAUM and RIPPLE, Circuit
Judges.
    FLAUM, Circuit Judge. One hundred police departments use
a surveillance network of GPS-enabled acoustic sensors called
ShotSpotter to identify gunfire, quickly triangulate its loca-
tion, and then direct oﬃcers to it. As a matter of first impres-
sion, this case requires us to consider whether law enforce-
ment may constitutionally stop a vehicle because, among
other articulable facts, it was emerging from the source of a
2                                                     No. 19-2054

ShotSpotter alert. The district court held that the totality of the
circumstances provided the oﬃcer responding to the scene
with reasonable suspicion of criminal activity to justify the
stop. We aﬃrm.
                         I. Background
   ShotSpotter is a surveillance system that uses sophisti-
cated microphones to record gunshots in a specific area. After
a device detects the sound of gunfire, it relays the audio file
to a server in California, where an individual determines
whether the sound is a shot. When that individual confirms
the sound is a gunshot, ShotSpotter sends it back to the local
police department.
    In the very early morning of July 29, 2018, Travis Elle-
fritz—an oﬃcer with the Peoria Police Department—was pa-
trolling the city in his squad car. At 4:40:02 a.m., the Depart-
ment’s ShotSpotter system reported two gunshots coming
from 2203 North Ellis Street. When Oﬃcer Ellefritz received
the ShotSpotter alert on his computer, he immediately started
driving toward the 2200 block of North Ellis. On his way, Of-
ficer Ellefritz heard the police dispatcher broadcast the
ShotSpotter alert he had just received. He then heard the dis-
patcher report a second ShotSpotter alert of three more shots
fired.
    Additionally, the dispatcher stated: “Cars en route to Ellis.
There are several cars leaving but seen going northbound on
McClure.” The dispatcher also reported a “black male on foot
who ran northbound on McClure.” As Oﬃcer Ellefritz ap-
proached the location, he switched his car lights oﬀ, turning
left from McClure Avenue onto North Ellis Street. He was the
first oﬃcer at the scene. Shortly thereafter, Oﬃcer Ellefritz
No. 19-2054                                                             3

saw a car’s headlights down the road and noticed it was leav-
ing North Ellis to come his way. This was the only vehicle Of-
ficer Ellefritz observed on the street.
    Upon seeing the headlights, Oﬃcer Ellefritz activated his
emergency lights and veered his vehicle into the lane of on-
coming traﬃc. As the approaching car slowed, Oﬃcer Elle-
fritz feared for a second that it was trying to get away from
him, so he shouted “stop” as he exited his vehicle at 4:45:23
a.m. Within seconds of this command, the car stopped next to
the left bumper of Oﬃcer Ellefritz’s cruiser.1 The car’s occu-
pants pointed backward, in the direction from where they
came, yelling: “They are down there! They are down there!”
Oﬃcer Ellefritz looked that way and observed a crowd of
about 15–20 people at the street’s dead end, approximately
300 feet from him.
     Oﬃcer Ellefritz kept his firearm drawn. He saw the de-
fendant, Terrill Rickmon, in the passenger seat. The driver
was the owner of the car. Both men kept their hands up until
backup arrived. At that time, Rickmon informed the oﬃcers
that someone had shot him in the leg. (Obviously, Oﬃcer Elle-
fritz did not know Rickmon was wounded when Ellefritz orig-
inally stopped the car.) With the driver’s consent, Oﬃcer Elle-
fritz searched the automobile and found a nine-millimeter
handgun under the passenger seat where Rickmon had been
sitting.




1The other car subsequently rolled back a few feet to a complete halt. Be-
cause this occurred after Officer Ellefritz already commanded the stop, it
does not factor into our analysis.
4                                                                 No. 19-2054

    Because of his criminal history, a federal grand jury in-
dicted Rickmon for possession of a firearm by a felon in vio-
lation of 18 U.S.C. § 922(g)(1). Rickmon moved pro se to sup-
press the firearm found by Oﬃcer Ellefritz, contending that
the Peoria Police Department did not have records showing
how many ShotSpotter reports were “false positive[s]” and
that other systems in cities across the country were inaccurate
and unreliable.
   On December 21, 2018, the district court presided over an
evidentiary hearing regarding Rickmon’s motion to sup-
press.2 Oﬃcer Ellefritz testified that, before the stop, he had



2 At certain points in this case, Rickmon has somewhat taken issue with
ShotSpotter’s reliability. A police department witness testified that, in
general, SpotShotter validates whether a sound is a gunshot within sec-
onds; however, in these specific circumstances, the witness was unable to
say how long that process took. The district court also received evidence
that SpotShotter is not always accurate and that officers may not solely
rely on it to locate gunfire. As Rickmon points out, the record here does
not demonstrate how often the Peoria Police Department received incor-
rect ShotSpotter reports or anything else attesting to the reliability of the
system. Still, the witness was subject to cross-examination about ShotSpot-
ter’s reliability. See Florida v. Harris, 568 U.S. 237, 247 (2013) (observing that
a defendant can challenge the reliability of certain evidence during cross-
examination); United States v. Bonds, 922 F.3d 343, 345–46 (7th Cir. 2019)
(similar). Rickmon, for his part, declined to further challenge ShotSpotter’s
adequacy. Cf. Harris, 568 U.S. at 248–49 (forfeiting similar argument). We
therefore take his argument as based on reasonable suspicion and need
not reach the reliability of ShotSpotter. In some future decision, we may
have to determine ShotSpotter’s reliability where a single alert turns out
to be the only articulable fact in the totality of the circumstances. See, e.g.,
State v. Hill, 851 N.W.2d 670, 691 (Neb. 2014) (holding that ShotSpotter
technology is reliable). But, in any event, this is not that case, given that
911 calls corroborated the ShotSpotter reports here and Rickmon himself
No. 19-2054                                                          5

no idea how many people were in the car or who was in the
car. Furthermore, he stated that he had no reason to suspect
that any weapons used in the shooting were in this car. He
explained that the occupants were not attempting to flee, they
complied with his commands, and they neither moved suspi-
ciously nor gestured threateningly. In sum, there was nothing
particularly unusual about this car, except for the fact that it
was leaving the area of the gunfire.
   Following the hearing, the district court denied Rickmon’s
motion, ruling that the traﬃc stop was objectively reasonable
based on the totality of the circumstances. The court reasoned:
       The short lapse of time between the dispatch
       and the stop, the 911 call of vehicles leaving the
       area, this vehicle being the only one Ellefritz
       saw in close proximity, less than 300 feet from
       where the shots were reported to have come
       from, the vehicle driving away from the area
       where shots reportedly originated, and upon
       seeing the patrol car stopping and then revers-
       ing slightly and moving away from Ellefritz,
       and the driver yelling that “they are still down
       there,” support the initial stop of that vehicle, if
       for no other reason than to inquire if they were
       witnesses to the shooting or to learn if they had
       been involved in the shooting.
   Rickmon conditionally pleaded guilty to the one-count in-
dictment and reserved his right to appeal the district court’s
denial of his motion to suppress. See Fed. R. Crim. P. 11(a)(2).

was in the system’s coverage zone. We express no further opinion on the
matter.
6                                                     No. 19-2054

On May 31, 2019, the district court sentenced Rickmon to 75
months in prison and accordingly entered judgment. This
timely appeal ensued.
                         II. Discussion
    Under the Fourth Amendment, police “oﬃcers may con-
duct a brief investigatory stop,” sometimes referred to as a
Terry stop, “if they reasonably suspect that an individual has
committed or is about to commit a crime.” Torry v. City of Chi-
cago, 932 F.3d 579, 587 (7th Cir. 2019) (citing Terry v. Ohio, 392
U.S. 1, 20–22 (1968)). “Reasonable suspicion requires specific
and articulable facts which, taken together with rational infer-
ences from those facts, suggest criminal activity.” United
States v. Lewis, 920 F.3d 483, 493 (7th Cir. 2019) (citation and
internal quotation marks omitted). We review the objective
reasonableness of a Terry stop de novo. See United States v.
Watson, 900 F.3d 892, 895 (7th Cir. 2018).
   “While ‘inarticulate hunches’ are not enough, ‘reasonable
suspicion is a lower threshold than probable cause’ and ‘con-
siderably less than preponderance of the evidence.’” United
States v. Adair, 925 F.3d 931, 935 (7th Cir. 2019) (citations omit-
ted). Our task is to objectively examine the “totality of the cir-
cumstances known to the oﬃcer at the time of the stop, in-
cluding the experience of the oﬃcer and the behavior and
characteristics of the suspect.” Id. (citation omitted). We are
mindful that “[r]easonable suspicion is a ‘commonsense, non-
technical’ concept that deals with ‘the factual and practical
considerations of everyday life on which reasonable and pru-
dent men, not legal technicians, act.’” United States v. Wanjiku,
919 F.3d 472, 488 (7th Cir. 2019) (citation omitted).
No. 19-2054                                                   7

    Rickmon argues that ShotSpotter, standing on its own,
should not allow police oﬃcers to stop a vehicle in the imme-
diate vicinity of a gunfire report without any individualized
suspicion of that vehicle. We generally agree with this propo-
sition. Indeed, we question whether a single ShotSpotter alert
would amount to reasonable suspicion. But we disagree with
Rickmon’s conclusion that, in this case, the oﬃcer had only an
“unparticular hunch”—rather than “specific and articulable
facts”—that the car connected back to the crimes. As the dis-
trict court found, the totality of the circumstances establishes
the oﬃcer stopped the car for more reasons than just its loca-
tion in ShotSpotter’s coverage zone.
    Rickmon is certainly correct that “[a] mere suspicion of il-
legal activity at a particular place is not enough to transfer
that suspicion to anyone who leaves that property.” United
States v. Bohman, 683 F.3d 861, 864 (7th Cir. 2012); see also
Ybarra v. Illinois, 444 U.S. 85, 91 (1979) (“[A] person’s mere
propinquity to others independently suspected of criminal ac-
tivity does not, without more, give rise to probable cause to
search that person.”).
    He likens his case to Bohman; however, that decision is dis-
tinguishable. As we have explained previously, “[i]n Bohman,
police stopped a car exiting property that oﬃcers suspected
of housing a methamphetamine lab. That suspicion resulted
from a tip they had received, but when police stopped the car,
they had not yet corroborated the tip in any way.” United
States v. Richards, 719 F.3d 746, 757 (7th Cir. 2013) (citation
omitted). We “found no reasonable suspicion for the stop be-
cause the only information pointing to criminal activity was
8                                                                 No. 19-2054

the defendant’s emergence from property that an uncorrobo-
rated tip accused of housing a meth lab. That alone was insuf-
ficient.” Id. (citation omitted).
    Rickmon asserts that the sergeant in Bohman had, in fact,
more suspicion than Oﬃcer Ellefritz did here. He reasons that
ShotSpotter is less reliable than the informant there (or a wit-
ness in any other case) because it “does not provide any spe-
cific information about suspects or vehicles, it simply records
sounds.” Again, we can assume for the sake of argument that
Oﬃcer Ellefritz needed “something extra” beyond the
ShotSpotter report. But Rickmon mistakenly claims that the
only other information the oﬃcer had when he made the stop
was the radio dispatch. This was not the only other infor-
mation the oﬃcer had to go on, and that is why Rickmon is
unlike the defendant in Bohman.
    In cases where an oﬃcer stops a car departing a suspected
crime scene, we have considered a number of circumstances
relevant to our reasonable suspicion analysis: (1) the reliabil-
ity of any reports to police; (2) the dangerousness of the crime;
(3) the temporal and physical proximity of the stop to the
crime; (4) any description of the vehicle and relevant traﬃc;
and (5) the oﬃcer’s (or potentially even the department’s) ex-
perience with criminal activity in that area. See United States v.
Burgess, 759 F.3d 708, 710–11 (7th Cir. 2014); United States v.
Brewer, 561 F.3d 676, 679 (7th Cir. 2009).3 We now apply these
factors to Rickmon’s case.


3 It is clear from our caselaw that a car’s vicinity to a suspected crime scene

is rarely, if ever, the only articulable fact justifying a traffic stop. Moreover,
Rickmon’s apparent bright-line rule that an officer must always identify a
suspect or vehicle by matching real-time observation with a previous re-
port is anathema to our evaluation of the totality of the circumstances. See
No. 19-2054                                                                  9

    First, and as Rickmon concedes, Oﬃcer Ellefritz received
two ShotSpotter alerts and two dispatches reporting a shoot-
ing on North Ellis. The details gleaned from the 911 calls that
the dispatcher passed on to Oﬃcer Ellefritz highlight that he
did not merely act on uncorroborated information. Granted,
we take Rickmon’s point that ShotSpotter is not comparable
to an eyewitness or known informant; instead, we conclude it
is analogous to an anonymous tipster. So, what Oﬃcer Elle-
fritz ends up with is an anonymous tip from ShotSpotter that
the 911 calls then independently confirmed. “Corroboration
from multiple sources describing the general area and nature
of the same crime exceeds the single police tip that alone can
supply reasonable suspicion for a stop.” Burgess, 759 F.3d at
710; see also Florida v. J.L., 529 U.S. 266, 270–71 (2000) (similar).
   Here, the radio dispatches that Oﬃcer Ellefritz listened to
on his way to the site of the shooting corroborated the
ShotSpotter alerts by relaying accounts of cars leaving the
scene and an individual running away from the shooting.4


Harris, 568 U.S. at 245 (rejecting a bright-line rule in the probable cause
context because “[a] gap as to any one matter … should not sink the State’s
case; rather, that ‘deficiency … may be compensated for, in determining
the overall reliability of a tip, by a strong showing as to … other indicia of
reliability.’” (quoting Illinois v. Gates, 462 U.S. 213, 233 (1983))); see also
Brewer, 561 F.3d at 677–79 (concluding a traffic stop was reasonable even
though, as in this case, the officer had no description of the vehicle or its
occupants but did notice that it was the sole vehicle passing through the
area’s only exit in the middle of the night).
4 The government encourages us to rely on a later 911 call from an indi-
vidual at 2227 North Ellis reporting “a bunch of gunfire” and five cars
moving north as a circumstance relevant to our reasonable suspicion anal-
ysis. But the police dispatcher did not convey this additional information
to any of the officers en route. We need not rely on this fact to resolve this
10                                                             No. 19-2054

And “[m]ultiple … report[s] [of] shots fired in the same gen-
eral area, creat[es] heightened suspicion of a serious


appeal because it does not tip the scales one way or the other. Officer Elle-
fritz was on firm footing when he stopped Rickmon’s car without these
details.
     Even if this 911 call was decisive, however, it cannot justify the stop
anyway because Officer Ellefritz did not know about it. See Brewer, 561
F.3d at 677–78 (reasoning that facts learned after a traffic stop cannot sup-
port it post hoc) (citations omitted). Officer Ellefritz must have been able to
articulate his suspicion of Rickmon’s car when he stopped it and he cannot
now articulate facts that were then unavailable to him. See United States v.
Wilbourn, 799 F.3d 900, 909 (7th Cir. 2015). “The fact that the 911 operator
turned out, after the fact, to have additional information which would
have given the arresting officers reasonable suspicion cannot retroactively
make their actions objectively reasonable.” United States v. Colon, 250 F.3d
130, 138 (2d Cir. 2001) (citation omitted).
     The government maintains that we should contemplate the “collective
knowledge” of all law enforcement personnel, including the police dis-
patcher, who were in communication regarding the investigation. But the
government admits that the dispatcher did not broadcast this 911 call to
the responding officers. And “imputed knowledge does not trump actual
knowledge ….” United States v. Hicks, 531 F.3d 555, 560 (7th Cir. 2008) (ci-
tation omitted). By conceding that the dispatcher did not transmit the con-
tents of the 911 call to Officer Ellefritz, the government effectively rebutted
any presumption of communication (and thus in favor of collective
knowledge) between those two individuals. See United States v. Brown, 496
F.3d 1070, 1071 n.2 (10th Cir. 2007) (citing United States v. Shareef, 100 F.3d
1491, 1503–04 (10th Cir. 1996)).
    We conclude that the government cannot justify an investigative stop
based on information that a 911 caller provides to a dispatcher who does
not, in turn, notify the police on the scene. See Colon, 250 F.3d at 137 (“Im-
puting information known only to the civilian operator and not conveyed
to the dispatching and then arresting officers would extend the doctrine
beyond its current jurisprudential parameters and vitiate the privacy safe-
guards of the Fourth Amendment ….”).
No. 19-2054                                                     11

crime ….” Id. at 711. Oﬃcer Ellefritz therefore had a good
idea of what to be on the lookout for when he arrived.
    Second, Oﬃcer Ellefritz was responding to an emergency
report of shots fired, not one of general criminality. We have
repeatedly emphasized in our decisions that the inherent dan-
ger of gun violence sets shootings apart from other criminal
activity. See, e.g., id. at 710–11 (distinguishing Bohman from
Brewer because of the apparent lack of immediate danger in
Bohman). In Burgess, another case involving a shooting, we un-
derscored that “the threat to public safety was serious, and
the oﬃcers had to assume that it was continuing in process.”
Id. at 711; see also Brewer, 561 F.3d at 679 (explaining the police
“had a compelling reason to ask questions of the driver or
passenger of the sole vehicle departing from a building com-
plex in which shots had been fired (and not for the first time),
in order to protect the police oﬃcers who were about to enter
the complex.”).
    Indeed, an emergency report “can support an oﬃcer’s rea-
sonable suspicion with less objective evidence to corroborate
the report.” United States v. Williams, 731 F.3d 678, 684 (7th Cir.
2013) (citing United States v. Hicks, 531 F.3d 555, 559–60 (7th
Cir. 2008)). In Williams, we determined that an anonymous
911 call justified a stop where “there was a large group of peo-
ple being loud and waving guns in a location at which violent
crime and drug activity is regularly reported.” Id. This rule
requiring less substantiation before making a stop based on
an emergency report enables the police oﬃcer “to obtain for
his own safety and that of the other oﬃcers as much infor-
mation about the situation in the [area] as he could before
they entered it in the dark.” Brewer, 561 F.3d at 678.
12                                                   No. 19-2054

    Third, Oﬃcer Ellefritz encountered Rickmon’s vehicle on
the same block of the shooting five-and-a-half minutes after
he received reports of shots fired. Rickmon claims that no
criminal in their right mind would stick around a crime scene
for that long. But we are not so sure. We know the shooting
continued after the initial ShotSpotter alert. Moreover, this
time frame is consistent with others in our caselaw. See, e.g.,
Burgess, 759 F.3d at 709 (“Just over four minutes had passed
from the initial dispatch about gunshots to the oﬃcers’ report
that Burgess was in custody.”); Brewer, 561 F.3d at 677 (noting
that oﬃcers observed the suspicious car minutes after the
original radio dispatch). Common sense counsels that a per-
son may take minutes rather than seconds to flee for any num-
ber of reasons, including the destruction of evidence, an in-
jury sustained in the shooting, or a need to hide in place. As
both a matter of fact and law, then, five-and-a-half minutes is
not unduly long.
    Rickmon’s vehicle was also driving away from the site of
the shooting on the only street leading from it. See United
States v. Street, 917 F.3d 586, 594 (7th Cir. 2019) (“The totality
of circumstances, however, may provide additional and rea-
sonable limits, particularly with respect to place and time, so
as to allow a stop based on a fairly general description.”).
Considering the facts here, it was a “natural surmise that
whoever fired the shots” would be in the vehicle that Oﬃcer
Ellefritz stopped. Brewer, 561 F.3d at 678; see also Burgess, 759
F.3d at 711 (stating that “the oﬃcers had … a street location
to zero in on” when a car “pass[ed] them (going the other way
and out of the area)” so “one might reasonably expect the
shooter’s vehicle” to be that one). Based on these facts, it was
No. 19-2054                                                   13

rational for Oﬃcer Ellefritz to infer that Rickmon’s car partic-
ipated in the gunfight because it was the only vehicle on the
street of the shooting.
     Fourth, Oﬃcer Ellefritz did not have the description of any
vehicle; however, it was 4:45 a.m. and there was no other traf-
fic. Again, in such a scenario, “[t]he hour reinforce[s] the sus-
picion” because we realistically expect few people on the road
at that time. Brewer, 561 F.3d at 678; see also Burgess, 759 F.3d
at 711 (“And because of the light traﬃc late on that Sunday
night, there was a good chance that seeing Burgess’s car at
that time and place was more than a coincidence.”). Hence, it
was reasonable—not random—to pull Rickmon over. See
Brewer, 561 F.3d at 679 (ruling that the responding oﬃcer “was
not acting randomly in deciding that the only car emerging
from the apartment complex moments after he heard shots
from within it should be intercepted”).
     Fifth, and finally, Oﬃcer Ellefritz knew that he was head-
ing toward a block that he once patrolled and where in the
past he had responded to shots-fired calls. Indeed, he esti-
mated that he responded to these couple blocks once per
night. To be fair, there was no evidence in the record that this
was a so-called “high crime area.” Instead, Oﬃce Ellefritz tes-
tified that he had personal knowledge of criminal activity in
that part of Peoria. He was of course right to “draw on his
own experience and specialized training to make inferences
from and deductions about the cumulative information avail-
able … that might well elude an untrained person.” United
States v. Hill, 818 F.3d 289, 294 (7th Cir. 2016) (quoting United
States v. Arvizu, 534 U.S. 266, 273 (2002)); see also Brewer, 561
F.3d at 679 (bearing in mind that the oﬃcer “had three years’
experience with criminal activity in the particular housing
14                                                        No. 19-2054

complex …”). Simply put, we have never required oﬃcers “to
ignore the relevant characteristics of a location in determining
whether the circumstances are suﬃciently suspicious to war-
rant further investigation.” Illinois v. Wardlow, 528 U.S. 119,
124 (2000).
    Altogether, the circumstances here—the reliability of the
police reports, the dangerousness of the crime, the stop’s tem-
poral and physical proximity to the shots, the light traﬃc late
at night, and the oﬃcer’s experience with gun violence in that
area—provided reasonable suspicion to stop Rickmon’s vehi-
cle. As in similar past challenges to automobile seizures,
“there is ‘far more in this case … than … mere physical prox-
imity’ to the criminal activity.” Richards, 719 F.3d at 758 (quot-
ing United States v. Burrell, 963 F.2d 976, 987 (7th Cir. 1992));
see also Burgess, 759 F.3d at 710. Multiple circumstances sepa-
rate Rickmon’s case from others. In isolation, any one of those
circumstances might not be suﬃcient.5 But viewed collec-
tively, they start to seem suspicious. “In such a situation, it is
reasonable for police to act quickly lest they lose the only op-
portunity they may have to solve a recent violent crime or to
interrupt an advancing one.” Burgess, 759 F.3d at 711.
                           III. Conclusion
    For the reasons stated above, the district court appropri-
ately denied Rickmon’s motion to suppress. We therefore
AFFIRM Rickmon’s resulting conviction and sentence.




5 Even then, “Terry accepts the risk that officers may stop innocent peo-
ple.” Wardlow, 528 U.S. at 126.
No. 19-2054                                                    15

    WOOD, Chief Judge, dissenting. If the Fourth Amendment
stands for anything, it stands for the proposition that the po-
lice cannot seize anyone without adequate, individualized
reason to do so. Sometimes that reason must provide proba-
ble cause for the seizure; sometimes it is enough that the po-
lice have reasonable suspicion pointing to the person de-
tained. But, with the exception of general roadblocks that sat-
isfy the standards articulated in City of Indianapolis v. Edmond,
531 U.S. 32 (2000)—a situation that all agree is not present in
the case before us—the police cannot simply force every per-
son or every car to stop, in the hopes that they might uncover
evidence of a crime. That would amount to a general warrant,
precisely the evil that the drafters of the Fourth Amendment
wanted to avoid.
    The question before us in this case is whether Oﬃcer
Travis Ellefritz, of the Peoria (Illinois) Police Department, had
the requisite individualized suspicion to order the car in
which defendant Terrill Rickmon was riding to stop. Ellefritz
was responding to two diﬀerent reports he received around
4:40 a.m. of gunshots having been fired in the immediate area
of the 2200 block of North Ellis Street, within the city limits of
Peoria. North Ellis is a two-block street that dead-ends at its
south end, intersects with Archer Street in the middle, and
“T’s” into West McClure Avenue at its north end. Top to bot-
tom, North Ellis is a little more than 430 yards (four football
fields plus a little).
    The majority recognizes that the validity of the stop rises
or falls based only on the knowledge Ellefritz had at the time
he stopped the car; no later-acquired facts can retroactively
save it. Here is what he knew, and how he knew it:
16                                                   No. 19-2054

          The ShotSpotter system in his squad car registered
           multiple gunshots at 2203 North Ellis around 4:40
           a.m. on July 29, 2018.
          That address is near the south end of the street,
           where it dead-ends.
          The police dispatcher announced two “shots fired”
           alerts detected by ShotSpotter over the radio.
          The police dispatcher informed Ellefritz that a 911
           call had come in reporting gunfire on North Ellis.
          The 911 caller also said that there were several cars
           leaving the location and one black male on foot.
          Between three and a half and five minutes after re-
           ceiving the initial ShotSpotter dispatch, Ellefritz
           reached North Ellis Street.
          As he drove south on the street, he saw a car turn
           from the east side of the street and proceed north-
           bound. He saw no other cars on the road.
Based on that information, Ellefritz decided to stop the car. He
turned on his emergency lights, maneuvered his car to block
the northbound land, and the car began to stop. It came to a
complete halt when Ellefritz yelled at the occupants to stop
and stay where they were.
    The only thing that distinguished the car Ellefritz chose to
stop was that it existed, and it was the only car on the street at
that early hour of the morning. None of the information he
had received even hinted at the shooter’s car’s make, color,
age, style, or anything else. Indeed, though I do not rely on
this subjective fact, Ellefritz frankly admitted that he would
No. 19-2054                                                    17

have stopped literally any car he saw on North Ellis based on
the information he had.
    It appears that it is illegal for a person to discharge a gun
within the corporate limits of Peoria, other than at a licensed
shooting gallery, gun club, or rifle club. Peoria City Ordi-
nance, sec. 20-161(a). It was thus reasonable for Ellefritz to
think that the discharge of a gun was unauthorized, despite
all the changes in gun regulation that have followed the Su-
preme Court’s decision in District of Columbia v. Heller, 554
U.S. 570 (2008). But virtually nothing connected those sounds
with the car he decided to stop, or indeed with any car at all—
it was just as likely that the shooter had retreated into a nearby
house or fled on foot (as the 911 caller indicated).
    My colleagues are willing to assume that because, some
five minutes after the shots were heard, this was the only car
on North Ellis, the people in it must have been associated with
the shots. But that is pure speculation. July 29 fell on a Sunday
in 2018. Nonetheless, some workplaces operate on a seven-
day week, and early-morning shifts are by no means unheard-
of: think of production workers, grocery stockers, transporta-
tion workers, bakers, and baristas, to name just a few. Or the
driver might have needed to go from Peoria to Chicago, or
Springfield, or St. Louis, for social reasons or a business ap-
pointment and wanted an early start. Or maybe the driver
was at a late party. The time of day, and the fact that the road
was largely empty, do not add up to anything.
   The 911 caller reported a man running away from the area
where the noises were heard, but Ellefritz did not stop a run-
ning man. And the street is so short – about a quarter of a mile
(one lap around a track)—that the runner would have been
long gone before Ellefritz pulled up in his car. Again, one
18                                                  No. 19-2054

could speculate that the shooter stayed around and then got
into the car that Ellefritz stopped. But that speculation is ut-
terly unsupported. It was equally plausible to speculate that
(a) the shooter ran across the grass to the parking lot south of
the dead end and quickly slipped out of sight, or (b) the
shooter took refuge in one of the surrounding houses, or (c)
the shooter crossed over Archer Street and rendezvoused
with his ride a safe block away.
    My colleagues also stress that Ellefritz believed that he was
responding to an emergency, because gunshots always con-
note emergency. Perhaps they do. But how much does this
prove? Would it have entitled the police to force their way
into every house on North Ellis, to make sure that the shooter
was not threatening anyone in those houses? Would it have
allowed the police to stop any and every car they saw within
1,000 feet of the point that ShotSpotter identified? My answer
to both those questions is no. And I cannot agree with my col-
leagues that a single car proceeding north, at the speed limit,
signals an emergency. There was some talk in the district
court about North Ellis being part of a “high crime” area, but
my colleagues admit that “there was no evidence in the record
that this was a so-called ‘high crime area.’” Ante at 13.
    Finally, my colleagues worry that compliance with the
Fourth Amendment here might have allowed a culpable per-
son to avoid being arrested. But there are two responses to
this point. First, the requirement that the police must have ei-
ther probable cause or at least reasonable suspicion before ar-
resting someone will, in some instances, hamper their activi-
ties. That is exactly what happened in Ybarra v. Illinois, 444
U.S. 85 (1979), when the Supreme Court held constitutionally
impermissible a search warrant that allowed the police to
No. 19-2054                                                    19

search, pat down, and seize any of the patrons of a small tav-
ern. It did so despite the fact that the search revealed that Ven-
tura Ybarra possessed heroin. Second, Rickmon’s oﬀense was
being a felon in possession of a firearm. To this day, no one
has suggested that he was the shooter. If anything, the fact
that his leg had been wounded by a bullet indicated (after the
fact) that he was a victim of the shooter.
   I would hold that Rickmon’s motion to suppress the evi-
dence should have been granted, and I would remand for fur-
ther proceedings. I therefore respectfully dissent.
