                          In the
 United States Court of Appeals
              For the Seventh Circuit
                       ____________

No. 04-4114
HALIMA ABDULLAHI, on her own
behalf and as Administrator for the
Estate of JAMAL MOHAMED, Deceased,
                                         Plaintiff-Appellant,
and ALI MOHAMED ABDI,
whereabouts unknown,
                           Involuntary Plaintiff-Appellant,

                             v.

CITY OF MADISON, SERGEANT PATRICK
GRADY, OFFICER HERBERT MUELLER,
OFFICER JESSICA MURPHY and CAPITOL
POLICE OFFICER JAMES BROOKS,
                                       Defendants-Appellees.
                       ____________
          Appeal from the United States District Court
              for the Western District of Wisconsin.
        No. 03-C-0631—Barbara B. Crabb, Chief Judge.
                       ____________
   ARGUED JUNE 8, 2005—DECIDED SEPTEMBER 12, 2005
                     ____________


 Before CUDAHY, EVANS and WILLIAMS, Circuit Judges.
 CUDAHY, Circuit Judge. Plaintiff Halima Abdullahi,
mother of a man who died during (or shortly after) defen-
2                                                  No. 04-4114

dant police officers’ attempts to subdue and arrest him,
brought a Fourth Amendment Claim against the City of
Madison and the police officers involved, alleging that
one of the officers used excessive force during the arrest and
that the other officers failed to intervene. The district court
granted defendants’ motion for summary judgment, ruling
that there was no evidence that the officers engaged in any
objectively unreasonable conduct. Plaintiff now appeals. For
the reasons set forth here, we reverse and remand.


    I.   FACTUAL BACKGROUND & DISPOSITION
         BELOW1
  This case marks the tragic final chapter of a troubled life.
Decedent Jamal Mohamed, the son of Somali immigrants,
suffered from severe Post Traumatic Stress Disorder
(PTSD) due to various traumatic experiences he endured as
a child in his homeland. As a result, he was prone to having
“episodes” of disorientation and erratic behavior. Mr.
Mohamed was apparently having one of these episodes on
the fateful afternoon of November 20, 2002.
  At approximately 1:18 p.m. on that day, nurse Pamela
McCarty was in her Jeep on her way to work when she
noticed the decedent staggering across three lanes of traffic
on University Avenue in Madison, Wisconsin. She observed
that he was breathing heavily and in apparent physical
distress, and he stumbled and fell as he attempted to
negotiate the curb. Ms. McCarty got out of her Jeep and
attempted to assist Mohamed, at which point he attempted


1
   These facts are taken principally from the district court’s
Opinion and Order below, Abdullahi et al. v. City of Madison
et al., 2004 WL 2535426, at *1-6 (Nov. 5, 2004, W.D.Wis.) (Un-
published Opinion and Order). Most of the basic facts surrounding
Mohamed’s encounter with the defendant police officers are not
disputed.
No. 04-4114                                                 3

to climb into her Jeep, threw himself against the vehicle,
ran back out into traffic, threw debris at her and then
grabbed her hair and clawed at her uniform. McCarty
attempted to free herself by hitting Mohamed in the head
with her cell phone, and she ultimately succeeded after
Mohamed had punched her once in the face.
  Meanwhile, defendant City of Madison Police Officer
Jessica Murphy received dispatches reporting that a male
was causing a disturbance in a tailor’s shop in the 2800
block of University Avenue. As she was driving to Univer-
sity Avenue, she received further dispatches alerting her to
Mohamed’s altercation with McCarty by the roadside. When
Murphy arrived at the scene of the altercation, she observed
Mohamed lying on his back on the sidewalk near the curb.
Fearing that Mohamed might need medical attention, she
called for fire rescue. As Murphy approached, Mohamed sat
up and began swinging his belt over his head by the buckle.
  Defendants Sergeant Patrick Grady and City of Madi-
son Officer Herbert Mueller were also on patrol in the
area when they heard the dispatches related to Mohamed.
When they heard additional radio transmissions that
Mohamed may have grabbed a pedestrian and was swinging
a belt at officer Murphy, they sped to the scene on
an emergency basis. Defendant State Capitol Officer James
Brooks was also in the area. After seeing Murphy’s squad
car speeding toward the scene with its siren activated,
Brooks got into his squad car, turned on his scanner and
headed in Murphy’s direction. While en route he heard a
female officer say something to the effect of “he’s whipping
his belt at me” and “step it up.”
  Shortly thereafter, Brooks and Grady arrived at the
scene. They observed that Mohamed was flailing with his
belt and making a guttural, growling noise. Brooks testified
that, as he approached, Mohamed jumped up from his knees
to a standing position, a move so “athletic” that it “shocked”
4                                                No. 04-4114

him. Defendants Grady, Murphy and Brooks them moved in
to subdue Mohamed. Murphy grabbed one of Mohamed’s
arms while Brooks and Grady grabbed the other. The three
officers moved Mohamed up against the Jeep to gain control
over him and then took him to the ground, onto his stom-
ach. Brooks testified that it was the most “peaceful”
takedown he had ever been a part of.
  Once on the ground, Mohamed began kicking his legs,
moving his arms so they could not be handcuffed and
arching his back upwards as if he were trying to escape.
Grady attempted to control Mohamed’s legs, and Murphy,
who was on Mohamed’s left, was able to cuff his left hand.
At some point during the encounter, defendant officer
Mueller arrived on the scene and grabbed Mohamed’s
right thigh and ankle in an attempt to keep him under
control. Defendant Brooks was on Mohamed’s right side,
and he placed his right knee and shin on the back of
Mohamed’s shoulder area and applied his weight to keep
Mohamed from squirming or flailing. Brooks increased the
pressure on Mohamed’s back until Mohamed stopped
arching his back upward. Mohamed apparently stopped
struggling about 15-20 seconds after Brooks began to
apply his weight to Mohamed’s shoulder area, and Brooks
was able to cuff Mohamed’s right wrist and connect the
handcuffs to those that Murphy had applied on Mohamed’s
left wrist. Brooks took his weight off Mohamed after the
handcuffing was complete. In all, Brooks estimates that his
knee and shin were on the back of Mohamed’s shoulder for
approximately 30-45 seconds.
  Brooks testified that Mohamed was still breathing after
the handcuffing was completed and Brooks had got off him.
Grady, who was trying to maintain control of Mohamed’s
legs, suggested that Mohamed’s legs be restrained. By this
time, several other police officers had gathered at the scene,
and one of them (Officer Morovic) ran to his squad car to
retrieve a kickstop restraint. At some point during this
No. 04-4114                                                        5

sequence of events (the parties differ on this point) Officer
Jerry Goehring walked up to the scene.2 Goehring did not
observe any movement from Mohamed, and the defendant
police officers all soon realized that Mohamed was not
breathing. Mueller and Grady, who were still holding onto
Mohamed’s legs, felt him go limp, and Brooks and Grady
both said something to the effect that Mohamed was no
longer breathing.
  Fire rescue workers had just arrived at the scene, and the
police officers removed all restraints so that paramedics
could initiate resuscitation efforts. Mohamed died at 2:39
p.m., approximately two and a half minutes after the
defendant officers had taken him to the ground.
  Plaintiff filed the present suit on November 10, 2003,
alleging that Officer Brooks used excessive, deadly force
to subdue her son Jamal Mohamed by kneeling on his
back while he was lying prone on the ground, causing chest
and neck trauma ultimately resulting in his death, in
violation of the decedent’s Fourth Amendment rights. She
also brought Fourth Amendment claims against the other
defendant police officers—Murphy, Grady and
Mueller—under 42 U.S.C. § 1983, alleging that they
observed Brooks using an unreasonable level of force
against Mohamed and failed to intervene.


2
   Plaintiff insists that Goehring arrived prior to Morovic’s
retrieval of the kickstop restraint, while the district court and
the defendants maintain that Goehring arrived at the scene
only after Morovic had begun to apply the kickstop. Plaintiff
insists that Goehring’s testimony regarding the timing of his
arrival creates inconsistencies in the officers’ collective testimony
as to when Mohamed stopped breathing. But ultimately not much
turns on this point since under either version of events
it is undisputed that Brooks’ knee was already off Mohamed’s
back when Goehring approached, and that Mohamed stopped
breathing shortly after Brooks’ knee was removed.
6                                               No. 04-4114

  Four different doctors provided medical testimony
regarding the cause of Mohamed’s death. They all agree
that Mohamed died of chest and neck trauma, including
a collapsed left lung and injuries consistent with strangula-
tion. They all observed that a tremendous amount of
air had been forced into the tissue surrounding Mohamed’s
lungs, as if his chest had been crushed or squashed. The
medical experts differ as to their certainty about the
exact cause or timing of these injuries.
  Dane County Coroner John Stanley officially listed the
cause of death as “(a) Traumatic Asphyxia, (b) Truncal
Emphysema/Tension; Pneumothorax [collapsed lung]/
Laryngeal [neck area] hemorrhage, (c) Neck and Chest
trauma.” (PRFF (Madison) at ¶ 78.) However, he was
not able to explain the exact causes of the trauma, stat-
ing that the origins of the collapsed lung and neck hem-
orrhage remain an “unanswered question.” (Id. at ¶¶ 20-
21.) Defendant Brook’s Expert, Dr. Robert W. Huntington
III, who performed the initial autopsy on Mohamed,
testified that he had never seen such a severe neck hemor-
rhage before, and he was unable to determine the exact
cause or timing of the injuries. He did say that Mohamed’s
injuries were consistent with strangulation and “would
strongly suggest force while he was alive,” though he said
they presented a “real conundrum” since they were not
explained by the defendant police officers’ accounts of their
encounter with Mohamed. (PRFF at ¶ 43, S.J. Exh. K at 5.)
Dr. Billy Bauman, hired by defendants Grady, Mueller and
Murphy (the Madison city police officers), opined that
Mohamed’s injuries did not occur during his struggle with
the defendant police officers, though he concedes that the
injuries could have been the result of blunt force trauma
and might have been related to Brooks’ kneeling on
Mohamed if Brooks had knelt on Mohamed’s neck. (PPFF
at ¶¶ 60-62.)
    Finally, plaintiff’s medical expert, Dr. Howard Adelman,
No. 04-4114                                                 7

concurred that Mohamed died of trauma to the chest
and neck, including a collapsed lung, and suffocation.
He asserts that Mohamed’s injuries were caused by trauma
or force inflicted upon the decedent while he was still alive.
He noted that these types of injuries occur “when the chest
is compressed by an external weight or force and is pre-
vented from expanding,” creating a physiological chain of
events “akin to drowning.” (Adelman Aff., S.J. Exh. G at
18.) Dr. Adelman also concluded “to a high degree of
medical probability and virtual certainty” that Mohamed’s
injuries “occurred during the struggle with the police
officers,” after he was already face-down on the ground. (Id.
at 19.) Dr. Adelman reasons that Mohamed could not
possibly have offered the resistance attributed to him by the
defendants if he had been suffering from such traumatic
injuries at the beginning of the encounter. Dr. Adelman also
noted that the officers reported no visible injuries or
difficulty breathing before taking Mohamed to the ground,
and that his internal wounds were bloody and fresh when
his body arrived in the coroner’s office for examination.
   Nurse McCarty and another civilian witness, Ms.
Weinfurter, were standing near the scene of the incident
(McCarty was standing 6-7 feet away), and they testi-
fied that Mohamed acted aggressively and that the de-
fendant police officers did not hit, strike or choke Mohamed,
nor do anything that might have caused him serious injury.
  Following discovery, defendants moved for summary
judgment and the district court granted this motion on
November 4, 2005, ruling that plaintiff had adduced no
evidence that Brooks had acted unreasonably under the
circumstances, nor that he had caused the injuries to
Mohamed’s neck and chest. The court noted the absence
of any eyewitness testimony suggesting that the police
acted violently or unreasonably, and the court asserted that
the mere fact of an injury does not suffice to create
a question of fact regarding excessive force. Abdullahi et al.
8                                                No. 04-4114

v. City of Madison et al., 2004 WL 2535426 (Nov. 5, 2004,
W.D.Wis.) (Unpublished Opinion and Order). Plaintiff’s
appeal now comes before us.


    II. JURISDICTION
  The district court had jurisdiction over the plaintiff’s
constitutional and section 1983 claims under 28 U.S.C.
§§ 1331 and 1343. The district court entered its judgment
granting the defendants’ motion for summary judgment
on November 9, 2004, and the plaintiff timely filed her
notice of appeal on December 1, 2004. We now have juris-
diction over the present appeal pursuant to 28 U.S.C. §
1291.


    III. DISCUSSION
  Plaintiff advances two claims here: (1) that defendant
Brooks used excessive force in subduing Mohamed and (2)
that the remaining defendants failed to intervene to stop or
prevent the application of excessive force. Though legally
distinct, the fate of plaintiff’s failure to intervene claim is
closely linked to that of her excessive force claim since, by
definition, if there was no excessive force then there can be
no failure to intervene.




    A. Excessive Force
  Under prevailing Supreme Court precedent, “all claims
that law enforcement officers have used excessive
force—deadly or not—in the course of an arrest, investiga-
tory stop, or other ‘seizure’ of a free citizen should be
analyzed under the Fourth Amendment and its ‘reasonable-
ness’ standard.” Graham v. Connor, 490 U.S. 386, 395
No. 04-4114                                                  9

(1989) (emphasis in original). Accord Brosseau v. Haugen,
125 S.Ct. 596, 598 (2004) (citing Graham and applying this
same standard); Lawrence v. Kenosha County, 391 F.3d 837,
843 (7th Cir. 2004) (same). This inquiry involves “a careful
balancing of the nature and quality of the intrusion on the
individual’s Fourth Amendment interests against the
countervailing governmental interests at stake.” Graham,
490 U.S. at 396 (citations and quotation marks omitted).
Not surprisingly, this analysis is “not capable of precise
definition or mechanical application” but “requires careful
attention to the facts and circumstances of each particular
case, including the severity of the crime at issue, whether
the suspect poses an immediate threat to the safety of the
officers or others, and whether he is actively resisting arrest
or attempting to evade arrest by flight.” Id. (citations and
quotation marks omitted). See also Tennessee v. Garner, 471
U.S. 1, 8-9 (1985) (the relevant question is “whether the
totality of the circumstances justifie[s] a particular sort of
. . . seizure”).
  Additionally, “the ‘reasonableness’ of a particular use
of force must be judged from the perspective of a reasonable
officer on the scene, rather than with the 20/20 vision of
hindsight.” Graham, 490 U.S. at 396. In excessive force
claims, “[t]he calculus of reasonableness must embody
allowance for the fact that police officers are often forced to
make split-second judgments—in circumstances that
are tense, uncertain, and rapidly evolving—about the
amount of force that is necessary in a particular situation.”
Id. at 396-97. Finally, “[a]s in other Fourth Amendment
contexts, the ‘reasonableness’ inquiry in an excessive force
case is an objective one: the question is whether the officers’
actions are ‘objectively reasonable’ in light of the facts and
circumstances confronting them, without regard to their
underlying intent or motivation.” Id. at 397. Cf. Scott v.
United States, 436 U.S. 128, 137-39 (1978); Terry v. Ohio,
392 U.S. 1, 21 (1968) (in analyzing the reasonableness of a
10                                               No. 04-4114

particular search or seizure, “it is imperative that the
facts be judged against an objective standard”).
  In the present case the excessive force claim is narrowly
defined—it concerns only defendant Brooks’ conduct during
the arrest, and specifically his kneeling on Mohamed’s
back/shoulder area after he was already lying prone with
his hands behind him. Plaintiff does not contest the reason-
ableness of attempting to restrain Mohamed, or of placing
him on the ground in a prone position. In granting defen-
dant police officers’ motion for summary judgment below,
the district court determined that there was no evidence
that Brooks did anything unreasonable. The court implied
that the plaintiff was attempting to “put[ ] word in Brooks’s
mouth” by arguing that there was a question of fact regard-
ing where Brooks placed his knee or how much force he
applied. 2004 WL 2535426, at *8. The court found it
undisputed that Brooks’ knee was only on Mohamed’s
shoulder blade, not on his neck or spine. Id. at *9. The court
also noted that plaintiff has conceded that it was reasonable
to take Mohamed to the ground, handcuff him and place
him in leg restraints. Given these findings, the district
court concluded that “[t]he undisputed evidence shows that
defendant Brooks applied force to Mohamed’s body in a
manner and for a time period not likely to cause any serious
injury to Mohamed.” Id. at *10.
  The court also asserted that violations of police practices
were not determinative for liability purposes,3 and that,
absent evidence of objectively unreasonable conduct, the
mere fact that Mohamed’s injury may have been caused
by Brooks was insufficient to avoid summary judgment.
2004 WL 2535426 at *10-11. The district court summarized


3
  The plaintiff had introduced testimony from police practices
expert Dennis Waller, who testified that Brooks’ attempt to
restrain Mohamed violated standard police practices.
No. 04-4114                                                11

its conclusions by stating that
    even if one agrees that plaintiff has some evidence that
    would support an inference that Mohamed was not
    injured before his encounter with the police officers,
    [the plaintiff’s] claim fails because she has adduced no
    evidence of specific wrongdoing . . . . no evidence to
    support her theory that Brooks applied force to
    Mohamed’s neck or chest, much less that he did so in a
    manner that carried a substantial risk of causing death
    or serious bodily harm . . . . Absent evidence that
    defendant Brooks’ actions were objectively unreason-
    able, plaintiff’s excessive force claim against defendant
    Brooks fails.
Id. at *12. In short, the district court concluded that
plaintiff’s claim hinges on speculation—rather than
evidence—of unreasonable conduct.
   We review the district court’s summary judgment rul-
ing de novo. Fix v. Quantum Indus. Partners LDC, 374 F.3d
549, 552 (7th Cir. 2004); Nevel v. Village of Schaumburg,
297 F.3d 673, 678 (7th Cir. 2002). Summary judgment is
warranted when the evidence, when viewed in a light most
favorable to the non-moving party, presents “no genuine
issue as to any material fact” such that “the moving party
is entitled to a judgment as a matter of law.” Fed. R. Civ. P.
56(c). See also Celotex Corp. v. Catrett, 477 U.S. 317, 322-23
(1986). In applying this standard, all disputed issues of fact
are to be resolved in favor of the non-moving party. Ander-
son v. Liberty Lobby, Inc., 477 U.S. 242, 255 (1986).
  Viewing all the evidence, as we must, in the light most
favorable to the plaintiff, we are satisfied that there remain
sufficient factual questions to reach a jury, and thus that
the district court’s grant of summary judgment was errone-
ous. It is undisputed that (1) Brooks knelt on Mohamed’s
shoulder or back for 30-40 seconds while Mohamed was
prone on the ground, and (2) Mohamed died roughly two
12                                                  No. 04-4114

minutes later of severe injuries consistent with pressure or
crushing trauma to the chest and neck area. There is
competent expert medical testimony that Mohamed suffered
these injuries after being put on the ground by the arresting
officers. Based on these straightforward facts alone, there
is an issue of material fact as to whether Brooks used an
unreasonable amount of force against Mohamed. No one
contends that deadly force was justified once Mohamed was
lying prone on the ground with his arms behind him, see
Garner, 471 U.S. at 11 (ruling that deadly force is justified
only where the officer “has probable cause to believe that
the suspect poses a threat of serious physical harm, either
to the officer or others”), and yet the record supports an
inference that Brooks knelt on Mohamed with enough force
to inflict lethal injuries. Accordingly, it is for a jury, and not
for us, to weigh all the evidence and choose between com-
peting inferences.
   Of course the plaintiff’s claim must fail if Brooks’ conduct
is considered reasonable as a matter of law. The defendant
police officers contend—and the district court so ruled—that
Brooks’ efforts to subdue Mohamed were objectively reason-
able under the circumstances. Both the defendants and the
district court rely heavily on Brownell v. Figel, 950 F.2d
1285 (7th Cir. 1991), and Estate of Phillips v. City of
Milwaukee, 123 F.3d 586 (7th Cir. 1997), in making this
argument. However, a careful reading reveals that these
cases are not particularly helpful to the defendants’ cause.
  In Brownell, we rejected an excessive force claim ad-
vanced by a plaintiff who was involved in a car accident,
was taken unparalyzed to a hospital and was subsequently
found to be paralyzed after leaving the hospital and be-
ing in police custody. Even conceding that the plaintiff may
have been in police custody while he suffered his injury, we
refused to indulge plaintiff’s “logic akin to the doctrine of
res ipsa loquitur.” 950 F.2d at 1292. Though there was
No. 04-4114                                                    13

ample evidence that plaintiff “left the hospital able to
move and returned a quadriplegic,” absent any evidence
of specific unreasonable conduct on the part of the offi-
cers, plaintiff’s claim was doomed. Id. A plaintiff may not
simply claim that the facts support an inference of “exces-
sive force, the precise nature of which has yet fully to come
to light.” Id. The Court also noted that “although not
dispositive, no evidence was presented that Brownell
returned to the hospital with bruises or other signs of
excessive force.” Id. at 1293.
  Phillips concerned the arrest of a an extremely over-
weight individual with preexisting health problems that
were not “observable to the untrained eye.”4 123 F.3d at
594. After taking decedent to the ground and subduing
him in a manner very similar to the technique used by
the defendant officers in this case,5 the officers left him
lying face-down on the ground with his hands handcuffed
behind him for approximately five minutes. Decedent’s
weight, his position on the ground and (apparently) his
preexisting health problems caused him to suffocate. In
rejecting the excessive force claim brought by the decedent’s
estate, the court ruled that “placing a person in a prone
position while handcuffed on the floor does not, in and of
itself, violate the Fourth Amendment,” and it determined
that there was no evidence that the police failed to take
reasonable steps to monitor decedent’s breathing. Id. The
court also cited Brownell for the proposition that claims
sounding in res ipsa loquitur do not suffice—the plaintiff


4
  Decedent’s health problems, in addition to obesity, included
an enlarged heart, an enlarged thyroid, Graves’ disease and a
thyroid storm.
5
  Phillips does support the notion that defendant police officers’
initial restraint and takedown of Mohamed was reasonable;
however, this issue is not is dispute.
14                                               No. 04-4114

must identify specific acts of misconduct by the officer(s) in
question. Id. Yet here again, the Court noted that “[t]he
medical evidence and witness testimony in this case shows
that the officers did not punch, slap, kick or otherwise
deliver a blow to Mr. Phillips’ body.” Id. at 593.
   These two cases stand for the proposition that the
mere fact that an injury occurred while an individual was
in police custody is not sufficient to avoid summary
judgment—a plaintiff must identify the specific unreason-
able conduct that caused his or her injuries. However, in the
case before us the plaintiff has identified the speci-
fic misconduct at issue—Brooks placing his knee on
Mohamed’s back—and she has introduced competent
medical evidence indicating that it caused deadly in-
juries. This is not a case where plaintiff’s theory of liabil-
ity rests merely on the apparent occurrence of an injury
while in police custody (like Brownell), or on the police’s
alleged failure to monitor a physically distressed prisoner
(like Phillips). Rather, here it is alleged that Brooks knelt
on the decedent’s back with chest-crushing force, and the
undisputed medical evidence reveals that decedent died
of injuries consistent with a crushing or squashing-
type trauma. As the plaintiff points out, the courts in both
Brownell and Phillips noted that the relevant medical
evidence did not reveal injuries consistent with excessive
force. In the present case, the opposite is true. The plaintiff
                                                             ’s
claim here thus involves different facts, a different theory
of liability and a crucial difference in the undisputed
medical evidence than Brownell or Phillips. Those cases do
not control the outcome here.
  The defendants also place special importance on the
fact that no eyewitness to the arrest reported seeing anyone
hit, slap, strike or choke Mohammed. They distinguish the
present case from others in which police violence was more
pronounced or aggravated. See, e.g., Champion v. Outlook
Nashville, Inc., 308 F.3d 893 (6th Cir. 2004) (police sat on
No. 04-4114                                                15

a prone, restrained man and continued to pepper spray him
for seventeen minutes); Drummond v. City of Anaheim, 343
F.3d 1052 (9th Cir. 2003) (police knocked Drummond to a
prone position, one police officer knelt on him with both
knees on his back, another officer placed one knee on
Drummond’s neck, and the officers laughed at Drummond’s
protests that they were choking him); Frazell v. Flanigan,
102 F.3d 877 (7th Cir. 1996) (officers kicked Frazell and
beat him repeatedly with their night sticks after he was
restrained).
  Certainly, Brooks’ conduct in this case does not appear to
be as cruel or wanton as that at issue in the cited cases, but
the evidence still supports an inference that it was unrea-
sonable. All other details aside, it is undisputed that he
knelt on Mohamed’s back during the arrest. The reasonable-
ness of kneeling on a prone individual’s back during an
arrest turns, at least in part, on how much force is applied.
Kneeling with just enough force to prevent an individual
from “squirming” or escaping might be eminently reason-
able, while dropping down on an individual or applying
one’s full weight (particularly if one is heavy) could actually
cause death.
  Of course, Brooks maintains that he knelt only on
Mohamed’s right shoulder, and only with enough force to
keep him from “squirming.” But, contrary to the district
court’s suggestions, his is not the only possible account
of the incident. The plaintiff asserts that Brooks knelt
on Mohamed’s back or neck with enough force to crush
his chest cavity, collapse his left lung and inflict severe
trauma on Mohamed’s neck—and Dr. Adelman’s medical
report suggests that he may have done just that. All the
medical experts in this case agree that Mohamed died of
a collapsed lung and other injuries consistent with ex-
treme external pressure, and Dr. Adelman asserted “to a
high degree of medical probability and virtual certainty”
that plaintiff suffered these injuries while being subdued by
16                                                  No. 04-4114

police. Viewed in this light, Mohamed’s undisputed at-
tempts to “squirm” or arch his back upward while he was
being restrained may not constitute resistance at all, but
rather a futile attempt to breathe while suffering from
physiological distress “akin to drowning.”
   While the district court suggested that Adelman’s report
is “conclusory” and that its admissibility at trial is an “open
question,” 2004 WL 2535426, at *11, even brief expert
reports will suffice at the summary judgment stage. See
Vollmert v. Wisconsin Dept. of Transp., 197 F.3d 293, 300-01
(7th Cir. 1999) (to avoid summary judgment, a party’s
expert need not “give a primer on why the facts allow the
expert to reach that conclusion”). Similarly, the plaintiff’s
proffered expert testimony that Brooks’ tactics violated
standard police practices, while not dispositive,6 may also be
deemed relevant to the reasonableness inquiry, as might
the plaintiff’s evidence that Brooks was aware of
Mohamed’s mental disabilities. See Brooks PRFF ¶¶ 59-68;
Drumond, 343 F.3d at 1057-58 (decedent’s mental disability
must be taken into account in the reasonableness inquiry);
Deorle v. Rutherford, 272 F.3d 1271, 1282-83 (9th Cir. 2001)
(same).
  In light of this evidence, plaintiff is correct that she is not
asking the finder of fact to speculate about the cause
of Mohamed’s death (as the district court has contended)
but rather is asking the fact finder to infer causation,
logically, from undisputed facts and competent evidence.
Such inferences are often necessary when the plaintiff’s sole
eyewitness is dead. Similarly, the fact that the available
eyewitnesses support the defendants’ account of things does



6
  “42 U.S.C. § 1983 protects plaintiffs from constitutional
violations, not violations of state laws or, in this case, depart-
mental regulations and police practices.” Scott v. Edinburg,
346 F.3d 752, 760 (7th Cir.2003) (citations omitted).
No. 04-4114                                                      17

not preclude the possibility of genuine factual questions.
The sheer number of witnesses mustered by each side is not
a relevant consideration, Unterreiner v. Volkswagen of
America, Inc., 8 F.3d 1206, 1214 (7th Cir. 1993) (“Perhaps
Unterreiner could have recruited other employees to offer
affidavits confirming his own recollection of things, but that
would only have affected the quantity of the evidence on his
side, not the quality. The number of witnesses for each
party is not dispositive at trial, let alone on summary
judgment.”), and cases may always be proven by circum-
stantial evidence where direct evidence is unavailable,
Murrell v. Frank, 332 F.3d 1102, 1117 (7th Cir. 2003)
(“Circumstantial evidence is of equal probative value to
direct evidence and in some cases is even more reliable.”).
Were it otherwise, a plaintiff might never prevail on an
excessive force claim where the victim is dead and the
defendant-police officer is the sole living eyewitness.7
  We have previously held that medical evidence and other
circumstantial evidence can be sufficient to create triable
issues of fact in excessive force cases. See Frazell v.
Flanigan, 102 F.3d 877, 884 (7th Cir. 1994), abrogated
on other grounds by Saucier v. Katz, 533 U.S. 194
(2001) (“Consistent with the medical evidence . . . the jury
could have determined that the officers had used force
against [plaintiff] far more frequently than they were



7
  See Plakas v. Drinski, 19 F.3d 1143, 1147 (7th Cir.), cert. denied,
513 U.S. 820 (1994): “The award of summary judgment to the
defense in deadly force cases may be made only with particular
care where the officer defendant is the only witness left alive to
testify. In any self-defense case, a defendant knows that the only
person likely to contradict him or her is beyond reach. So a court
must undertake a fairly critical assessment of the forensic
evidence, the officer’s original reports or statements and the
opinions of experts to decide whether the officer’s testimony could
reasonably be rejected at a trial.” (Emphasis added.)
18                                                     No. 04-4114

willing to admit.”).8 Certainly plaintiff’s proffered
evidence—including Adelman’s expert testimony—must be
weighed against the eyewitness accounts offered by the
defendants themselves and the two civilian onlookers (all of
whom contend that the defendants did nothing untoward9).
The conflicting conclusions of the medical experts must also
be reconciled. But this is just another way of saying that
there is a genuine issue of fact as to the excessive force
claim, which must be sorted out by a jury. Concluding that
Brooks knelt only on Mohamed’s right shoulder and applied
only reasonable force with his knee (as did the district
court) ineluctably implies crediting Brooks’ account of the
incident and discounting Dr. Adelman’s medical testimony.
This, of course, is improper at summary judgment. At
summary judgment a court may not assess the credibility of


8
  The Ninth Circuit also recently made a ruling to this effect in
a case raising analogous factual questions:
     Here, the officers admit to having applied force when re-
     straining Santos. A jury might find believable the officers’
     contentions that they did so gently, and accordingly might
     return a verdict in their favor. Alternatively, a jury might find
     the officers’ testimony that they were restrained in their use of
     force not credible, and draw the inference from the medical
     and other circumstantial evidence that the plaintiff ’s injuries
     were inflicted on him by the officers’ use of excessive force.
     After all, broken backs do not ordinarily result from the type
     of gentle treatment described by Officer Lee.
Santos v. Gates, 287 F.3d 846, 852 (9th Cir. 2002) (emphasis
added).
9
  One cannot discount the eyewitness accounts out of hand
(especially not at the summary judgment stage), though it is an
open question whether anyone could tell, merely by looking,
how much force Brooks applied to Mohamed’s back or shoulder.
Certainly one could see whether anyone applied a choke hold
to Mohamed, but, as mentioned above, the plaintiff apparently
does not advance such a claim.
No. 04-4114                                                  19

witnesses, choose between competing inferences or balance
the relative weight of conflicting evidence; it must view all
the evidence in the record in the light most favorable to the
non-moving party and resolve all factual disputes in favor
of the non-moving party. Anderson v. Liberty Lobby, Inc.,
477 U.S. 242, 255 (1986).
   When the facts here are viewed, as they must be, in the
light most favorable to the plaintiff, there remains a
question of fact as to whether Brooks knelt at the location
and in the restrained manner that he claims. Simply put,
the cumulative weight of the medical evidence—particularly
Dr. Adelman’s testimony—combined with the undisputed
testimony of Brooks’ conduct during the arrest, supports an
inference of unreasonable conduct, even if the eyewitness
testimony does not.10 As one of our sister circuits has
observed, since the Graham reasonableness inquiry “nearly
always requires a jury to sift through disputed factual
contentions, and to draw inferences therefrom, we have held
on many occasions that summary judgment or judgment as
a matter of law in excessive force cases should be granted
sparingly.” Santos, 287 F.3d at 853. We agree. The ruling of
the district court with respect to plaintiff’s excessive force
claim must be reversed and the case remanded for further
proceedings.



10
   The dissent’s suggestion that the medical reports are “hind-
sight” is misleading. Hindsight refers to the application of
unrealistic standards to past events. The fact that the evidence
here was necessarily acquired post mortem does not suggest
that the evaluation of it was anything but realistic. Cause-of-
death evidence must always be evaluated after the fact; the
question is whether such medical evidence reveals that the
defendant officers’ conduct was unreasonable in light of the
circumstances of the arrest as they were unfolding. Drawing
inferences as to the reasonableness of police conduct in this
manner does not impermissibly rely on “hindsight.”
20                                                 No. 04-4114

  B. Failure to Intervene
   This leads us to the plaintiff’s claim against officers
Grady, Mueller and Murphy. Under Yang v. Hardin, 37
F.3d 282 (7th Cir. 1994), “[a]n officer who is present
and fails to intervene to prevent other law enforcement
officers from infringing the constitutional rights of citizens
is liable under § 1983 if that officer had reason to know: (1)
that excessive force was being used, (2) that a citizen has
been unjustifiably arrested, or (3) that any constitutional
violation has been committed by a law enforcement official;
and the officer had a realistic opportunity to intervene
to prevent the harm from occurring.” Id. at 285 (emphasis
in original). This Court has implied that a “realistic oppor-
tunity to intervene” may exist whenever an officer could
have “called for a backup, called for help, or at least cau-
tioned [the excessive force defendant] to stop.” Id. Perhaps
more crucially, this Court has made clear that the prongs of
this analysis almost always implicate questions of fact for
the jury: “Whether an officer had sufficient time to inter-
vene or was capable of preventing the harm caused by the
other officer is generally an issue for the trier of fact unless,
considering all the evidence, a reasonable jury could not
possibly conclude otherwise.” Lanigan v. Village of East
Hazel Crest, Ill., 110 F.3d 467, 478 (7th Cir. 1997) (empha-
sis added).
   Yet even under this stringent standard, the question here
is a close one. There is little direct evidence suggesting that
Grady, Mueller and Murphy should have recognized that
illegal conduct was occurring, or that they had a reasonable
opportunity to intervene. As a general matter, it would be
difficult to infer such facts solely from the kind of medical
evidence introduced here, and all of the available eyewit-
nesses suggest that Brooks’ actions did not appear unrea-
sonable. On the other hand, it is undisputed that Mueller,
Grady and Murphy were mere feet away from Brooks while
the conduct in question occurred, and the plaintiff has also
No. 04-4114                                                21

introduced expert testimony that Brooks’ efforts to restrain
Mohamed violated standard police practices. While the
question certainly gives us pause, we must conclude, under
these circumstances and in light of the severity of
Mohamed’s injuries, that questions of fact remain with
respect to the intervention claim no less than for the
underlying excessive force claim.
  Depending upon how the jury evaluates the evidence
of Brooks’ conduct, it could conclude, consistent with the
evidence, that one or more of the other officers could and
should have attempted to prevent Mohamed’s injuries.
Based on the medical evidence, a jury could determine
that Brooks choked or otherwise abused Mohamed in a
fashion visible to onlookers. At the least, a reasonable jury
might conclude (if the plaintiff’s theory of the case is
credited) that the other officers should have cautioned
Brooks to stop kneeling on Mohamed’s back. Cf. Yang, 37
F.3d at 285. Such a conclusion would render the plaintiff’s
intervention claim quite tenable. Thus, given that the
excessive force claim against Brooks is not amenable to
summary judgment, the associated failure to intervene
claims must go to trial as well. The parties have not
identified any consideration that would warrant stray-
ing from this Court’s directive in Lanigan, which in-
structs that the intervention inquiry should be left to the
jury.
  As a last-ditch effort to win the day, defendants argue (in
just three pages of their appellate brief) that they
are entitled to qualified immunity. In Harlow v. Fitzgerald,
457 U.S. 800 (1982), the Supreme Court held that “govern-
ment officials performing discretionary functions generally
are shielded from liability for civil damages insofar as their
conduct does not violate clearly established statutory or
constitutional rights of which a reasonable person would
have known.” Id. at 818. Thus, in order to survive summary
judgment on grounds of qualified immunity, a plaintiff must
22                                               No. 04-4114

(1) allege violation of a valid legal right and (2) demonstrate
that “it would be clear to a reasonable officer that his
conduct was unlawful in the situation he confronted.”
Saucier, 533 U.S. at 201-02.
  Here the plaintiff has certainly alleged violation of a valid
constitutional right—if defendant Brooks applied deadly
force to Mohamed while he was lying prone on the ground
with his arms behind him, this would violate Mohamed’s
Fourth Amendment rights, as would an unjustifiable failure
by the other officers to intervene. However, whether it
would have been clear to a reasonable officer that Brooks’
actions constituted unreasonable force under the circum-
stances—thus triggering the duty to intervene—is obviously
a more difficult question. Presumably, if it would have been
apparent to the other officers, just by watching, that Brooks
was applying potentially deadly pressure to Mohamed while
he was lying prone, then the officers would not be entitled
to qualified immunity. Again, no one contends that deadly
force was warranted in this case.
  However, it may have been difficult to tell how much force
Brooks was applying, and at least one or two of the officers
(those attempting to restrain Mohamed’s legs) had their
back to Brooks during the encounter. Additionally, this
Court’s 1997 decision in Estate of Phillips ruled that a
similar takedown—during which one officer put a knee in
Phillips’ back for about one minute—was not unreasonable
under the circumstances. 123 F.3d at 593. However, since
the very nature of Brooks’ conduct remains undetermined,
one can only speculate as to how visually obvious any
violation of Mohammed’s rights might have been. In other
words, without knowing what Brooks did or how his conduct
appeared to onlookers, it would be difficult to say that, as a
matter of law, a reasonable officer could not have known
that Brooks’ conduct violated Mohamed’s constitutional
rights. A jury should decide whether Brooks’ actions would
have made it clear to a reasonable officer that intervention
No. 04-4114                                                  23

was warranted, and, if so, whether Grady, Mueller and
Murphy had a realistic opportunity to intervene.
  Accordingly, we also reverse the district court’s grant
of summary judgment in favor of the defendants on plaintiff’s
failure to intervene claim and remand this claim for further
proceedings as well.11


     IV. CONCLUSION
  For the foregoing reasons, we REVERSE the district court’s
grant of summary judgment in favor of the defendants and
REMAND the case for further proceedings not inconsistent
with this opinion.




  EVANS, Circuit Judge, dissenting. Although I agree, as
the majority observes, that this case marks the “tragic final
chapter” in the life of Jamal Mohamed, I do not think his
survivors offer sufficient evidence to keep the case going
any longer. I would affirm Judge Crabb’s order granting
summary judgment for the defendants.
  As the majority notes, “the plaintiff’s claim must fail if
Brooks’ conduct is considered reasonable as a matter of
law,” a standard discussed at length in Brownell and
Phillips. The majority reads those cases to “stand for the
proposition that . . . a plaintiff must identify the specific


11
   Obviously, there is substantial evidence exculpating all four
of the officers, which will be heard by the jury.
24                                               No. 04-4114

unreasonable conduct that caused his or her injuries.” The
majority distinguishes those cases by finding that, unlike
Brownell and Phillips, the plaintiff here (Mohamed’s
mother) identifies specific unreasonable conduct—Brooks
pushing down on Mohamed’s back—and presents sufficient
medical evidence to support the claim.
   While Brooks’ actions might well have caused Mohamed’s
death, I part company with the majority on the question of
whether the evidence is sufficient to show that his actions
were in any way unreasonable under the circumstances. In
answering that question, the majority cites the medical
report suggesting that Brooks might have pushed too hard
on Mohamed’s back or neck while trying to restrain him.
Relying on that report, however, ignores the well-estab-
lished rule that a police officer’s conduct in a struggle like
the one that occurred here must be judged from the perspec-
tive of a reasonable officer on the scene, not the “20/20
vision of hindsight.” Graham v. Connor, 490 U.S. 386, 395
(1989).
   It was that understanding of the law, and not just
the failure of the plaintiffs to identify specific conduct,
that led us to reject “logic akin to the doctrine of res ipsa
loquitur” in a situation like the one we have here. See
Phillips, 123 F.3d at 594; Brownell, 950 F.2d at 1292.
By relying on the medical records to support the plain-
tiff’s claim that Brooks might have pressed too hard,
however, that is precisely the logic the majority uses. The
question is not whether, looking back, Brooks might have
pressed harder than he should have—in hindsight, perhaps
he did. Instead, though, we should ask only whether, at the
time, Brooks acted reasonably. And, given what appeared
to the police on the scene to be a very dangerous situation,
the plaintiff offers no evidence that Brooks’ actions, includ-
ing pushing down on Mohamed’s back to get him under
control, were unreasonable.
No. 04-4114                                                25

  Throughout the short encounter, Mohamed acted errati-
cally and violently. He punched nurse McCarty and began
swinging his belt over his head when Officer Murphy
approached him. He strenuously resisted as police tried to
handcuff him. It was only then—while a man, who had just
punched someone trying to help him, threateningly swung
his belt at a police officer, and tried to resist, even when on
the ground, as several officers tried to handcuff him—that
Brooks began applying weight to Mohamed’s back and
shoulder area. Brooks’ knee was on Mohamed for around a
half a minute, and Mohamed was breathing when Brooks
got up (suggesting that Brooks had no reason to know that
he was pressing too hard, if he in fact was). The plaintiff
offers absolutely no evidence to rebut this view of what
happened. As Judge Crabb observed, “[t]he undisputed
evidence shows that defendant Brooks applied force to
Mohamed’s body in a manner and for a time period not
likely to cause any serious injury to Mohamed.” That the
force applied may have, in fact, caused a fatal injury to
Mohamed is tragic, but it does not mean that the force
applied was unreasonable. For these reasons, I respectfully
dissent.

A true Copy:
       Teste:

                         ________________________________
                         Clerk of the United States Court of
                           Appeals for the Seventh Circuit




                    USCA-02-C-0072—9-12-05
