                 FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT


TERESA SHEEHAN,                            No. 11-16401
              Plaintiff-Appellant,
                                              D.C. No.
                  v.                       3:09-cv-03889-
                                                CRB
CITY AND COUNTY OF SAN
FRANCISCO, a municipal corporation;
HEATHER FONG, in her capacity as             OPINION
Chief of Police for the City and
County of San Francisco; KIMBERLY
REYNOLDS, individually, and in her
capacity as police officer for the City
and County of San Francisco;
KATHERINE HOLDER, individually,
and in her capacity as police officer
for the City and County of San
Francisco,
               Defendants-Appellees.


      Appeal from the United States District Court
        for the Northern District of California
      Charles R. Breyer, District Judge, Presiding

                 Argued and Submitted
      January 16, 2013—San Francisco, California

                 Filed February 21, 2014
2       SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

        Before: John T. Noonan, Susan P. Graber and
             Raymond C. Fisher, Circuit Judges.

                   Opinion by Judge Fisher;
    Partial Concurrence and Partial Dissent by Judge Graber


                           SUMMARY*


                            Civil Rights

    The panel affirmed in part and reversed in part the district
court’s summary judgment and remanded in an action
brought under 42 U.S.C. § 1983, the Americans with
Disabilities Act, and state law, alleging that police officers
violated plaintiff’s rights when they entered her residence
without a warrant and shot her after she threatened them with
a knife.

    The panel held that the officers were justified in entering
plaintiff’s home initially under the emergency aid exception
because they had an objectively reasonable basis to believe
that plaintiff was in need of emergency medical assistance
and they conducted the search or seizure in a reasonable
manner up to that point. The panel also held that the district
court properly rejected plaintiff’s claims of municipal liability
under Monell v. Department of Soc. Servs. of the City of New
York, 436 U.S. 658 (1978).




  *
    This summary constitutes no part of the opinion of the court. It has
been prepared by court staff for the convenience of the reader.
      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO              3

    The panel held that a jury could find that the officers
acted unreasonably by forcing a second entry into plaintiff’s
residence and provoking a near-fatal confrontation. The
panel held that plaintiff presented a triable issue of the
unreasonable use of deadly force under a provocation theory.
See Billington v. Smith, 292 F.3d 1177, 1189 (9th Cir. 2002).

    The panel held that Title II of the Americans with
Disabilities Act applies to arrests and on the facts presented
in this case, there was a triable issue whether the officers
failed to reasonably accommodate plaintiff’s disability when
they forced their way back into her room without taking her
mental illness into account or employing generally accepted
police practices for peaceably resolving a confrontation with
a person with mental illness. Finally, the panel vacated
summary judgment on plaintiff’s state law claims and
remanded for further proceedings.

    Concurring in part and dissenting in part, Judge Graber
stated that although she agreed with the remainder of the
opinion, she dissented from the majority’s decision on the
Fourth Amendment excessive force claim with respect to the
second entry into plaintiff’s apartment.


                        COUNSEL

John L. Burris and Benjamin Nisenbaum (argued), Law
Offices of John L. Burris, Oakland, California, for Plaintiff-
Appellant.
4     SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

Dennis J. Herrera, City Attorney, Joanne Hoeper, Chief Trial
Deputy, Blake P. Loebs and Peter J. Keith (argued), Deputy
City Attorneys, San Francisco, California, for Defendants-
Appellees.


                         OPINION

FISHER, Circuit Judge:

    This case involves a near fatal tragedy in which police
officers attempted to help a mentally ill woman who needed
medical evaluation and treatment but wound up shooting and
nearly killing her instead. They did so after entering her
home without a warrant, causing her to react with violent
outrage at the intruders. Fundamentally at issue is the
constitutional balance between a person’s right to be left
alone in the sanctity of her home and the laudable efforts of
the police to render emergency assistance, but in a way that
does not turn the intended beneficiary into a victim or a
criminal.

     Teresa Sheehan, a woman in her mid-50s suffering from
a mental illness, lived in a San Francisco group home that
accommodated such persons. Her assigned social worker,
Heath Hodge, became concerned about her apparently
deteriorating condition and summoned the police for help in
transporting her to a mental health facility for a 72-hour
involuntary commitment for evaluation and treatment under
California Welfare & Institutions Code § 5150. Hodge
deemed Sheehan “gravely disabled,” because she was not
taking her medication or taking care of herself, and a danger
to others, because she had threatened him when he attempted
to perform a welfare check on her. When San Francisco
      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO                5

police officers Kimberly Reynolds and Katherine Holder
arrived on the scene, they entered Sheehan’s room, without
a warrant, to confirm Hodge’s assessment and take her into
custody. Sheehan reacted violently to the officers’ presence,
grabbing a knife, threatening to kill the officers, telling the
officers that she did not wish to be detained in a mental health
facility and forcing the officers to retreat to the hallway,
outside Sheehan’s closed door, for their safety. The officers
called for backup, but rather than waiting for backup or
taking other actions to maintain the status quo or de-escalate
the situation, the officers drew their weapons and forced their
way back into Sheehan’s room, presumably to disarm, subdue
and arrest her, and to prevent her escape (although there do
not appear to have been any means of escape available).
Sheehan once again threatened the officers with a knife,
causing the officers to shoot Sheehan five or six times.
Sheehan, who survived, filed this 42 U.S.C. § 1983 action
against the officers and the city, asserting violations of her
rights under the Fourth Amendment and the Americans with
Disabilities Act, as well as tort and statutory claims under
state law. The district court granted summary judgment to
the defendants, and Sheehan appealed.

    Although a warrantless search or seizure in a person’s
home is presumptively unreasonable under the Fourth
Amendment, our case law recognizes exceptions to the
warrant requirement to render emergency assistance or
respond to exigent circumstances. We hold that the officers
were justified in entering Sheehan’s home initially under the
emergency aid exception because they had an objectively
reasonable basis to believe that Sheehan was in need of
emergency medical assistance and they conducted the search
or seizure in a reasonable manner up to that point. Officers
conducting a welfare search, where the objective is rescue,
6     SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

are expected to err on the side of caution, and under the
circumstances of this case the officers reasonably could have
believed that Sheehan’s situation presented a genuine
emergency and that entering as they did was a reasonable
means of providing her with assistance.

    We nonetheless hold that there are triable issues of fact as
to whether the second entry violated the Fourth Amendment.
If the officers were acting pursuant to the emergency aid
exception, then they were required to carry out the search or
seizure in a reasonable manner. Similarly, if they were acting
pursuant to the exigent circumstances exception, they were
required to use reasonable force. Under either standard, a
jury could find that the officers acted unreasonably by forcing
the second entry and provoking a near-fatal confrontation.
We therefore cannot say that the second entry was reasonable
as a matter of law.

    We further hold that there are triable issues of fact as to
whether the officers used excessive force by resorting to
deadly force and shooting Sheehan. The shooting was lawful
when viewed from the moment of the shooting because at that
point Sheehan presented an immediate danger to the officers’
safety. Under our case law, however, officers may be held
liable for an otherwise lawful defensive use of deadly force
when they intentionally or recklessly provoke a violent
confrontation by actions that rise to the level of an
independent Fourth Amendment violation. See Billington v.
Smith, 292 F.3d 1177, 1189 (9th Cir. 2002). Here, Sheehan
has presented a triable issue as to whether the officers
committed an independent Fourth Amendment violation by
unreasonably forcing their way back into her home, and she
has also presented evidence from which a reasonable jury
could find that the officers acted recklessly in doing so. She
      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO                7

has therefore presented a triable issue of the unreasonable use
of deadly force under Billington’s provocation theory.

     We hold that the district court properly rejected Sheehan’s
claims of municipal liability under Monell v. Department of
Social Services of the City of New York, 436 U.S. 658 (1978).
Sheehan’s claim that the city is liable on a failure to train
theory fails because she concedes that the police department
employed appropriate training materials to guide police
officers’ responses to persons they knew to be suffering from
mental illness. That the officers may not have followed those
policies does not establish that the city was deliberately
indifferent to Sheehan’s rights. Sheehan’s claim that the city
is liable for ratifying the officers’ allegedly unconstitutional
acts fails because there is no evidence that the city adopted or
expressly approved the officers’ actions.

    Turning to an issue of first impression, we join the
majority of circuits that have addressed the issue and hold
that Title II of the Americans with Disabilities Act applies to
arrests. But we emphasize, as have those other circuits, that
the exigencies surrounding police officers’ decisions in the
field must be taken into account when assessing the
reasonableness of the officers’ actions. We hold that, on the
facts presented here, there is a triable issue whether the
officers failed to reasonably accommodate Sheehan’s
disability when they forced their way back into her room
without taking her mental illness into account or employing
generally accepted police practices for peaceably resolving a
confrontation with a person with mental illness.

   Finally, we vacate summary judgment on Sheehan’s state
law claims and remand for further proceedings.
8     SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

                     BACKGROUND

    Teresa Sheehan was a resident of Conrad House, a group
home for persons dealing with mental illness located in San
Francisco. Residents of the home have private rooms and
share common areas, like the kitchen and living room. On
August 7, 2008, Heath Hodge, a social worker, attempted to
perform a welfare check on Sheehan. When he entered
Sheehan’s room without her permission, Sheehan told him to
get out. She also told him that she had a knife and threatened
him.

    In light of Sheehan’s threat, Hodge cleared the building
of other residents. He also completed an application under
California Welfare & Institutions Code § 5150 for Sheehan’s
72-hour detention for psychiatric evaluation and treatment.
He telephoned the police department’s nonemergency number
and requested police assistance in transporting Sheehan to a
mental health facility.

    Section 5150 provides a mechanism for mental health
professionals or others to initiate a temporary detention of
persons who are a danger to themselves or others or “gravely
disabled.” Section 5150 states in pertinent part:

           When any person, as a result of mental
       disorder, is a danger to others, or to himself or
       herself, or gravely disabled, a peace officer,
       member of the attending staff, as defined by
       regulation, of an evaluation facility designated
       by the county, or other professional person
       designated by the county may, upon probable
       cause, take, or cause to be taken, the person
       into custody and place him or her in a facility
      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO               9

       designated by the county and approved by the
       State Department of Health Care Services as
       a facility for 72-hour treatment and
       evaluation.

Cal. Welf. & Inst. Code § 5150(a). The statute defines
“gravely disabled” as, inter alia, “[a] condition in which a
person, as a result of a mental disorder, is unable to provide
for his or her basic personal needs for food, clothing, or
shelter.” Id. § 5008(h)(1).

    The San Francisco Police Department dispatched Officer
Katherine Holder and Sergeant Kimberly Reynolds to
respond to Hodge’s call for assistance. The computer
automated dispatch information provided to the officers
stated: “Social worker just went inside to check on his
patient, subject is known to make violent threats, told
reporting party to get out or she’ll knife him (no weapon
seen) / / Name is Teresa Sheehan / Eurasian, early 50’s,
wearing striped shirt/pants.”

    Officer Holder and Sergeant Reynolds met Hodge outside
the group home. Hodge showed the officers a card issued by
the city identifying him as a person authorized to initiate a
72-hour detention under § 5150. Hodge advised the officers
of his reason for the call. He explained that he had gone into
Sheehan’s room to check on her and that Sheehan had
threatened to kill him with a knife. He explained that
Sheehan had been off her medication for a matter of months
and that she had not been taking care of herself. Hodge also
informed the officers that he had cleared the building of other
residents and that the only way out of Sheehan’s room, other
than the main door to the second floor hallway, was a second
10     SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

floor window that could not be used as a means of egress
without a ladder.1

   Hodge also showed the officers the § 5150 application he
had completed before their arrival. The application said:

        Client has been without psychotropic meds
        times one and a half years. Has been
        presenting with increased symptoms for
        several weeks. Client has not been seen by
        the house counselor times two weeks.
        Housemates reported that client has been
        coming and going at odd hours and reportedly
        said she had stopped eating. It was also
        reported that client has been wearing the same
        clothing for several days. Writer conducted
        outreach to client and she was not responsive.
        Made no sound behind her closed door.
        Writer and property management keyed in for
        wellness check. Upon opening the door,
        client was found lying in her bed with a book
        over her face, eyes open and was not
        responsive. Addressed client several times
        and she did not move or answer. Client then
        suddenly got up, threw the covers, and yelled
        at writer violently, “Get out of here! You
        don’t have a warrant! I have a knife and I’ll
        kill you if I have to!” Client then slammed
        her door and locked it behind her.


 1
   Whether Hodge told the officers that no one else was in the building
appears to be disputed, but for purposes of evaluating the defendants’
motion for summary judgment we view the evidence in the light most
favorable to Sheehan, the nonmoving party.
      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO             11

Near the bottom of the application form, Hodge checked two
boxes, one to indicate that Sheehan was a danger to others
and one to indicate that she was gravely disabled. Hodge did
not check the box to indicate that Sheehan was a danger to
herself, nor did he give the officers any other reason to
believe Sheehan was suicidal or likely to injure herself.

     Based on the information furnished by Hodge, the officers
decided to contact Sheehan to confirm Hodge’s assessment
and take Sheehan into custody. Sheehan’s room was located
at the end of a hallway on the second floor. As the officers
faced Sheehan’s closed door, there was a closed door to the
right and a small alcove, also containing closed doors, to the
left.

    When they reached Sheehan’s door, the officers,
accompanied by Hodge, knocked on the door and announced
that they were police officers. They used a key that Hodge
had given them and opened the door. When the door opened,
the officers saw Sheehan lying on her bed with a book on her
chest or stomach.

    What happened next is mostly, though not entirely,
undisputed. In Sergeant Reynolds’ telling, Sheehan “raised
up, reached over with her left hand very quickly grabbed one
of the knives, a larger knife, from the plate and immediately
walked in an aggressive threatening manner towards us
saying, get out of here. I’m going to kill you. Get out of my
room. I don’t need your help. Stuff like that, and was
repeating it over and over and over again.” The “knife was
shoved out in front of her, blade pointed towards us. She had
her hand on the . . . handle, and as she approached closer to
us the knife was always in front of her and there was some
moving going on, like a jabbing motion or a stabbing
12      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

motion.” In Officer Holder’s telling, Sheehan “grabbed the
knife” and “raised it above her head coming towards Sergeant
Reynolds and me saying I’m going to kill you.” Hodge
confirmed that Sheehan held a knife in her hands and said
several times that she would kill the officers if they came near
her. Although Sheehan’s version of events departs in certain
respects from those of the other three witnesses, Sheehan
concedes that she held a knife and threatened to kill the
officers.2 Sheehan testified that she told the officers that they
didn’t have a search warrant and that they needed to subpoena
her if they wanted to talk to her. She testified that she told
the officers to go away and leave her alone.

    This encounter ended when the officers retreated and
Sheehan closed the door, leaving Sheehan in her room and
the officers and Hodge in the hallway. The officers
responded to this situation by calling for backup, drawing
their service weapons and directing Hodge to go downstairs
to let in additional officers who would be responding to the
call for backup. Rather than waiting for backup to arrive,
however, the officers decided to forcibly reenter Sheehan’s
room. As Sergeant Reynolds later explained:

         With the door being closed and us not having
         the ability to see what she was doing, we had
         no way of knowing whether or not, one, she

 2
   Sheehan’s appellate briefs acknowledge that her deposition testimony
was conflicting and inconsistent. Her briefs state that “there were obvious
gaping inconsistencies in her testimony,” and that her “testimony also
smacks of irrationality that begs the question whether any of it is
credible.” They say that “the inherent inconsistencies in her testimony
cast suspicion over all of it.” With respect to some events, in fact,
Sheehan’s briefs adopt the officers’ version of events rather than
Sheehan’s own.
        SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO                      13

         . . . had an avenue of escape. Two, there were
         the possibility of other weapons that she could
         gain access to. And so in my opinion, as soon
         as that door was closed, the threat became
         more scary for us and more uncertainty about
         what we were dealing with.

Because Sheehan had “displayed obvious signs of violence
and wanting to kill” the officers, Reynolds deemed the entry
necessary to ensure officer safety and to prevent Sheehan
from escaping (and becoming a threat to others).
Consequently, Reynolds directed Holder to attempt to force
the door open. Reynolds acknowledges that she did not take
Sheehan’s mental illness into account when she decided to
force the second entry. As Holder used her feet and shoulders
to attempt to gain entry, Reynolds stood behind Holder with
her pepper spray in one hand and her service weapon in the
other. Holder also had her service weapon out. The door
opened.3

    What happened next is subject to some dispute. Under
the officers’ account, Sheehan emerged from the room
brandishing a knife and advanced on the officers. Reynolds
pepper sprayed Sheehan, but without effect. When Sheehan
continued to advance, Holder, and then Reynolds, fired their
weapons, hitting Sheehan five or six times. Sheehan fell to
the ground, but continued to swing the knife at the officers

   3
      The officers used considerable force in gaining entry. Sergeant
Reynolds first tried to get the door open, presumably by kicking and
shouldering it, without success. When she could not force it open, Officer
Holder took over. She unsuccessfully tried to kick it open. She then
resorted to using her shoulder. After four to six such attempts, the door
finally budged. The officers also had their firearms drawn, itself a
significant use of force.
14     SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

until a backup officer arrived and kicked the knife from
Sheehan’s hand. The officers testified that Sheehan was
between two and four feet from Holder when Holder first
fired – so close that Holder was forced to fire from the hip to
prevent Sheehan from cutting her arm.

    In Sheehan’s telling, she opened the door and showed the
officers the knife. She had the knife upraised in her right
hand and took one step toward the officers. This step placed
her on the threshold and it was at that point that she was
pepper sprayed by the officers. Sheehan testified:

        And then I screamed at them. You’re
        blinding me, you’re blinding me. I can’t see.
        And then I started . . . to fall. And they right
        away were shooting me. I started to come out
        the door because I was blinded. I had my
        knife in my hand. . . . I was wearing my
        glasses. And I started to raise my other arm.
        And then the shots happened. . . . And then I
        fell against the wall in the corridor. Close to
        the kitchen door.

After she fell to the floor, an officer kicked the knife from her
hand. Sheehan acknowledges that she continued to hold the
knife after she was pepper sprayed and shot. She also
concedes that it was her intent to resist arrest and to use the
knife to defend herself against the officers because she did
not want to be removed from her home or detained for a 72-
hour evaluation.

    There is some dispute over whether Sheehan was
standing, falling or had reached the ground when Reynolds
fired the final shot. Holder testified that Sheehan had already
      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO             15

reached the ground. Reynolds testified that Sheehan was still
standing. Sheehan testified that she was falling against the
wall.

    Sheehan survived the shooting, and the city prosecuted
her for two counts of assault with a deadly weapon, two
counts of assaulting a police officer with a deadly weapon
and one count of making criminal threats against Hodge. See
Cal. Penal Code §§ 245(a), (c), 422. The jury hung on the
four assault counts and acquitted on the criminal threats
count. The city elected not to retry Sheehan.

    Sheehan then filed this 42 U.S.C. § 1983 action against
the City and County of San Francisco, Police Chief Heather
Fong, Sergeant Reynolds and Officer Holder, alleging
violations of her Fourth Amendment rights against
unreasonable search and seizure, including a warrantless
search and use of excessive force. She also alleged violation
of her rights under the Americans with Disabilities Act and
state law claims for assault and battery, negligence,
intentional infliction of emotional distress and violation of
California Civil Code § 52.1. The district court granted the
defendants’ motion for summary judgment, and Sheehan
timely appealed.

                STANDARD OF REVIEW

     We review the district court’s summary judgment rulings,
including its rulings on qualified immunity, de novo. See
Maxwell v. Cnty. of San Diego, 697 F.3d 941, 947 (9th Cir.
2012). “Summary judgment should be granted ‘if the movant
shows that there is no genuine dispute as to any material fact
and the movant is entitled to judgment as a matter of law.’”
Id. (quoting Fed. R. Civ. P. 56(a)). We view the evidence in
16     SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

the light most favorable to Sheehan, the nonmoving party,
and draw all reasonable inferences in her favor. See id.

    Qualified immunity protects government officials 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. See Pearson
v. Callahan, 555 U.S. 223, 231 (2009). To determine
whether a government official is entitled to qualified
immunity, we conduct a two-part analysis. Government
officials are denied qualified immunity only if (1) the facts
that a plaintiff has alleged or proved show a violation of a
constitutional right and (2) the right at issue was clearly
established at the time of the defendant’s alleged misconduct.
See id. at 232. We have discretion in deciding which of the
two qualified immunity prongs should be addressed first. See
id. at 242.

                        DISCUSSION

               I. FOURTH AMENDMENT

    Sheehan contends that the officers violated her Fourth
Amendment rights by entering her home without a warrant
and using excessive force. We evaluate the officers’ actions
in the sequence in which they occurred.

                       A. Initial Entry

    We reject Sheehan’s contention that the officers violated
her Fourth Amendment rights by initially entering her home
without a warrant.
      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO              17

                              1.

    Searches and seizures inside a home without a warrant are
presumptively unreasonable, but that presumption is not
irrebuttable, and a warrantless search or seizure is permitted
to render emergency aid or address exigent circumstances.
See United States v. Struckman, 603 F.3d 731, 737-38 (9th
Cir. 2010). The emergency aid exception applies when:
“(1) considering the totality of the circumstances, law
enforcement had an objectively reasonable basis for
concluding that there was an immediate need to protect others
or themselves from serious harm; and (2) the search’s scope
and manner were reasonable to meet the need.” United States
v. Snipe, 515 F.3d 947, 952 (9th Cir. 2008). To satisfy the
exigency exception, the government must prove: (1) that the
officer had probable cause to search or arrest; and (2) that
exigent circumstances justified the warrantless intrusion. See
Hopkins v. Bonvicino, 573 F.3d 752, 766–67 (9th Cir. 2009).
Exigent circumstances include “those circumstances that
would cause a reasonable person to believe that entry . . . was
necessary to prevent physical harm to the officers or other
persons, the destruction of relevant evidence, the escape of
the suspect, or some other consequence improperly frustrating
legitimate law enforcement efforts,” United States v.
McConney, 728 F.2d 1195, 1199 (9th Cir. 1984) (en banc),
overruled on other grounds by Estate of Merchant v.
Comm’r, 947 F.2d 1390, 1392–93 (9th Cir. 1991), or when
police are in hot pursuit of a suspect, see United States v.
Johnson, 256 F.3d 895, 907 (9th Cir. 2001) (en banc) (per
curiam).

   A search or seizure conducted pursuant to either of these
exceptions must be carried out in a reasonable manner.
Under the emergency aid exception, “the search’s scope and
18    SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

manner [must be] reasonable to meet the need.” Snipe,
515 F.3d at 952; see also Brigham City v. Stuart, 547 U.S.
398, 406–07 (2006) (examining whether “[t]he manner of the
officers’ entry was also reasonable” under the emergency aid
exception). Similarly, under the exigent circumstances
exception officers are required to use reasonable force in
carrying out the search or seizure. As we said in Fisher v.
City of San Jose, 558 F.3d 1069 (9th Cir. 2009) (en banc),
where we applied the exigent circumstances exception:

       Nothing in today’s opinion . . . even hints at
       disturbing the Fourth Amendment
       requirement that the force, deadly or not, used
       in the course of arrest, investigatory stop, or
       other “seizure” of a person must satisfy the
       “objective reasonableness” standard. To be
       clear, we do not suggest that the initial
       exigency and seizure thereafter condoned
       unfettered force to resolve the armed standoff,
       discharged all of Fisher’s Fourth Amendment
       protections, or reduced in any way the
       probable cause needed to arrest. A court can
       certainly later examine the officers’ actions in
       connection with a suspect’s subsequent
       criminal trial or a collateral civil rights suit for
       other alleged Fourth Amendment violations,
       as the jury did here.

Id. at 1084 (citation omitted).

   Under the circumstances of this case, we see no
meaningful distinction between the emergency aid
exception’s requirement that a search or seizure be conducted
in a reasonable manner and the Fourth Amendment’s
        SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO                        19

requirement that it be carried out without the use of excessive
force. Both inquiries stem from the common principle that an
otherwise lawful search or seizure – whether justified by a
warrant or by an exception to the warrant requirement – “may
be invalid if carried out in an unreasonable fashion.”
Franklin v. Foxworth, 31 F.3d 873, 875 (9th Cir. 1994).
Thus, regardless of whether the officers rely on the
emergency aid exception or the exigent circumstances
exception, they were required to conduct the search or seizure
in a reasonable manner, using reasonable force. We therefore
apply the Supreme Court’s excessive force standard to both
inquiries.4

    Under that standard, “[d]etermining whether the force
used to effect a particular seizure is reasonable under the
Fourth Amendment requires 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 v. Connor, 490 U.S. 386, 396
(1989) (internal quotation marks omitted). This test of
reasonableness “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. The reasonableness of a particular use of force,
moreover, “must be judged from the perspective of a

  4
     It also immaterial whether we characterize the officers’ entry as a
search or a seizure. Regardless, they were required to use reasonable
force. See Hopkins, 573 F.3d at 776 (“It is clearly established that the use
of excessive force in effecting a seizure violates the Fourth
Amendment.”); Boyd v. Benton Cnty., 374 F.3d 773, 780 (9th Cir. 2004)
(“This Circuit has clearly recognized that the use of excessive force during
a search makes that search unreasonable under the Fourth Amendment.”).
20    SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

reasonable officer on the scene, rather than with the 20/20
vision of hindsight,” making “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.

                              2.

     Applying these standards here, we hold that the officers’
initial entry into Sheehan’s home was lawful under the
emergency aid exception.

    First, the officers had an objectively reasonable basis for
concluding that there was an urgent need to protect Sheehan
from serious harm. The officers knew that Sheehan was off
her medication, was not taking care of herself and had acted
in a threatening manner toward Hodge. They were also
aware that, in Hodge’s view, she was both “gravely disabled”
and in need of temporary, involuntary hospitalization to
receive psychological evaluation and treatment. Sheehan
points out that she may not have required immediate
assistance. Hodge had not suggested Sheehan was suicidal
and the conditions Hodge described – not eating, not taking
medication, not changing clothes – suggested a gradual rather
than a sudden deterioration. The officers, however,
reasonably took a cautious view of the situation. Hodge, who
was a trained social worker and personally familiar with
Sheehan’s condition, considered the situation dire enough to
apply for a § 5150 detention and to call for police assistance
in transporting Sheehan to a mental health facility. Hodge
had telephoned the police immediately after his encounter
with Sheehan, suggesting that the situation was urgent.
Sheehan’s threatening behavior toward Hodge suggested that
      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO              21

her condition had deteriorated precipitously, again suggesting
urgency. Under the circumstances, the officers acted
reasonably by treating the situation as a genuine emergency.
As we stated in United States v. Black, (9th Cir. 2007):

             This is a case where the police would be
       harshly criticized had they not investigated
       . . . . Erring on the side of caution is exactly
       what we expect of conscientious police
       officers. This is a “welfare search” where
       rescue is the objective, rather than a search for
       crime. We should not second-guess the
       officers[’] objectively reasonable decision in
       such a case.

Id. at 1040. See also Michigan v. Fisher, 558 U.S. 45, 49
(2009) (per curiam) (“Officers do not need ironclad proof of
‘a likely serious, life-threatening’ injury to invoke the
emergency aid exception.”).

    Second, the officers carried out the search or seizure in a
reasonable manner up to and including the initial entry.
Accompanied by Hodge, the officers knocked and announced
that they were police officers. They then used a pass key
supplied by Hodge to let themselves in for the purpose of
assessing whether Sheehan needed emergency treatment
under § 5150. Their weapons were not drawn and they had
no reason to believe that their entry would trigger a violent
confrontation. The officers therefore used reasonable force
under the circumstances.
22      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

   Accordingly, we hold that the officers’ initial entry into
Sheehan’s home did not violate the Fourth Amendment.5

                         B. Second Entry

    We hold, however, that there are triable issues of fact as
to whether the second entry violated the Fourth Amendment.

                                   1.

     We do not suggest that the officers are liable for acting
without a warrant. There are at least two, and possibly three,
reasons why the officers were permitted to act without a
warrant at the time of the second entry. First, the officers
continued to have an objectively reasonable basis for
concluding that there was an urgent need to protect Sheehan
from serious harm, satisfying the emergency aid exception’s
first prong. See Snipe, 515 F.3d at 952.6 The emergency that


  5
    Because we hold that the initial entry falls under the emergency aid
exception, we need not decide whether the exigent circumstances
exception would also apply. Nor need we address whether the officers’
warrantless entry may have been covered by a “special need” exception
to the warrant requirement. See Griffin v. Wisconsin, 483 U.S. 868, 873
(1987). The First and Third Circuits have held that a special need
exception applies when police officers enter a subject’s home to take her
into custody pursuant to a state law authorizing emergency hospitalization
of a person suffering from mental illness. See Doby v. DeCrescenzo,
171 F.3d 858, 872 (3d Cir. 1999); McCabe v. Life-Line Ambulance Serv.,
Inc., 77 F.3d 540, 553 (1st Cir. 1996). The parties have not raised that
issue here, however.
 6
  The two prongs of the emergency aid exception address distinct Fourth
Amendment requirements. The first prong – whether law enforcement
had an objectively reasonable basis for concluding that there was an
immediate need to protect others or themselves from serious harm –
        SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO                          23

existed at the time of the initial entry was no less apparent at
the time of the second entry. On the contrary, Sheehan’s
behavior toward the officers during their initial entry only
confirmed that her condition had deteriorated to the point of
creating an emergency. Second, because the two entries were
part of a single, continuous search or seizure, the officers are
not required to separately justify the continuing emergency
with respect to the second entry. See Michigan v. Tyler,
436 U.S. 499, 511 (1978) (“[W]e find that the morning
entries were no more than an actual continuation of the first,
and the lack of a warrant thus did not invalidate the resulting
seizure of evidence” where the initial entry was justified by
exigent circumstances); Fisher, 558 F.3d at 1077 (“[W]e
conclude that when Fisher was seized at the beginning of the
standoff, the officers were not required to periodically
reassess whether the exigency persisted throughout the
standoff because the standoff was ‘no more than an actual
continuation’ of the initial seizure.”); United States v. Kaplan,
895 F.2d 618, 623 (9th Cir. 1990); United States v.




addresses whether the officers proceeded lawfully by acting without a
warrant. The second prong – whether the search’s scope and manner were
reasonable to meet the need – addresses whether, even if a warrant was
not required, the officers carried out the search or seizure in an
unreasonable manner. A search or seizure comports with the Fourth
Amendment only if both prongs are satisfied. Cf. Fisher, 558 F.3d at
1080, 1084 (holding that the Fourth Amendment’s warrant requirement
was satisfied under the exigent circumstances exception but that the
officers still could be liable for carrying out the seizure in an unreasonable
manner). The first prong is satisfied here, justifying the officers for acting
without a warrant. But there are triable issues as to whether the second
prong is satisfied.
24       SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

Echegoyen, 799 F.2d 1271, 1280 (9th Cir. 1986).7 Third,
although the point is debatable, the officers may have been
justified in acting without a warrant under the exigent
circumstances exception.8 That the officers did not have a
warrant at the time of the second entry, therefore, did not
violate the Fourth Amendment.

                                   2.

    We are not persuaded, however, that the officers carried
out the search or seizure in a reasonable manner at the point
of the second entry. As we have explained, regardless of
whether the officers invoke the emergency aid exception or
the exigent circumstances exception, they were required to


     7
    Although the continuous search doctrine applies here, that doctrine
speaks only to the warrant requirement, not to the separate requirement
that officers carry out a search or seizure in a reasonable manner. See
Fisher, 558 F.3d at 1084. Thus, although the officers were not required
to reassess the existence of an emergency or the need for a warrant
periodically, they were required at all times to conduct the search or
seizure in a reasonable manner.
 8
   Because we hold that the absence of a warrant was justified under both
the emergency aid exception and the continuous search doctrine, we need
not address whether the exigent circumstances exception applies to the
second entry. Whether as a matter of law it would apply is at least
questionable. By the time of the second entry, the officers had probable
cause to believe Sheehan had committed a crime by threatening the
officers. Arguably, the officers could have avoided harm to themselves
by retreating a safe distance from the door; the knife was not in imminent
danger of destruction; there was no “hot pursuit” given that Sheehan “was
already inside the [room] when the police officers arrived,” Struckman,
603 F.3d at 744; and given that Hodge had informed them that the only
way out of the room was an inaccessible second story window, and
Sheehan had shown no interest in leaving her room, there was no reason
to fear Sheehan’s escape.
        SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO                       25

carry out the search or seizure in a reasonable manner,
without the use of excessive force. See Fisher, 558 F.3d at
1084; Snipe, 515 F.3d at 952. Although we have no trouble
with the manner in which the officers carried out the search
or seizure up to and including the initial entry, we cannot say
as a matter of law that the officers continued to carry out the
search or seizure in a reasonable manner when they decided
to force the second entry, without taking Sheehan’s mental
illness into account and in an apparent departure from their
police officer training.9

    Sheehan presented an expert report by Lou Reiter, a
former deputy chief of the Los Angeles Police Department.
We treat Reiter’s report as relevant evidence of
reasonableness, as we are required to do. Although we have
held that the mere fact that an expert disagrees with an
officer’s actions does not itself compel the conclusion that the
officer’s actions were unreasonable, see Billington v. Smith,
292 F.3d 1177, 1189 (9th Cir. 2002); Reynolds v. Cnty. of San
Diego, 84 F.3d 1162, 1170 (9th Cir. 1996), overruled on
other grounds by Acri v. Varian Assocs., Inc., 114 F.3d 999,
1001 (9th Cir. 1997), a rational jury may rely upon expert
evidence in assessing whether an officer’s use of force was
unreasonable, see Glenn v. Washington Cnty., 673 F.3d 864,
877 (9th Cir. 2011); Smith v. City of Hemet, 394 F.3d 689,


   9
     In examining whether the officers conducted the search or seizure in
a reasonable manner at the point of the second entry, we do not focus on
the amount of force they employed to force open the door (considerable)
and that they did so with their firearms drawn (itself a significant use of
force). See footnote 3, supra. Rather, we focus on their critical decision
to enter at all. See Alexander v. City & Cnty. of San Francisco, 29 F.3d
1355, 1366–67 (9th Cir. 1994) (holding that there were triable issues as to
whether officers used excessive force by storming the house of a mentally
ill recluse who had threatened to shoot anybody who entered).
26    SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

703 (9th Cir. 2005) (en banc); Reynolds, 84 F.3d at 1169.
Reiter’s report is therefore relevant to the excessive force
inquiry.

    Reiter described general police practices for dealing with
persons who are mentally ill or emotionally disturbed,
explaining that officers are trained not to unreasonably
agitate or excite the person, to contain the person, to
respect the person’s comfort zone, to use nonthreatening
communications and to employ the passage of time to their
advantage. He also cited materials used by the San Francisco
Police Department to train officers on “appropriate tactical
actions” to be used when confronting the mentally ill. These
materials, which are germane to the excessive force inquiry
because they were designed to protect individuals such as
Sheehan from harm, see Scott v. Henrich, 39 F.3d 912,
915–16 (9th Cir. 1994), advise officers to request backup, to
calm the situation, to communicate, to move slowly, to
assume a quiet, nonthreatening manner, to take time to assess
the situation and to “give the person time to calm down.”

    Reiter deemed the officers’ second entry into Sheehan’s
home tactically unreasonable under those policies. In his
view, the officers should have “elected to . . . relocate to a
safer tactical position, call for special units/equipment, and
determine the propriety of seeking a warrant.” He opined that
there was

       no logical reason that the officers did not pull
       back from the landing outside Ms. Sheehan’s
       private residence after their first attempt to
       enter.     The location was a tactical
       disadvantage for the officers. Both officers
       knew that Ms. Sheehan had refused their entry
      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO               27

       and made specific comments regarding the
       necessity for a warrant. They knew that other
       resources were en-route to their call for
       backup. Officer Holder’s and Sgt. Reynold’s
       [sic] continued conduct exacerbated the
       confrontation, rather than any effort to
       [defuse] the agitation.

    In view of Reiter’s report, the officers’ training and the
totality of the circumstances – viewing the facts favorably to
Sheehan as we must – we conclude that a reasonable jury
could find that the officers’ decision to force a confrontation
with Sheehan was objectively unreasonable. See Alexander
v. City & Cnty. of San Francisco, 29 F.3d 1355, 1366 (9th
Cir. 1994) (explaining that the operative question is whether
“the force the police used was unreasonable under all of the
circumstances”). Although Sheehan needed assistance, the
officers had no reason to believe that a delay in entering her
room would cause her serious harm, especially when weighed
against the high likelihood that a deadly confrontation would
ensue if they forced a confrontation. Sheehan was not
suicidal, cf. Fitzgerald v. Santoro, 707 F.3d 725, 731 (7th Cir.
2013); West v. Keef, 479 F.3d 757, 759 (10th Cir. 2007); Bias
v. Moynihan, 508 F.3d 1212, 1220 (9th Cir. 2007), or
bleeding to death. In addition, although the officers may have
been justified in believing that Sheehan had assaulted them
and should be arrested, under her version of the facts there
was no immediate need to subdue her and take her into
custody. A reasonable jury could find that Sheehan was in a
confined area and not a threat to others – so long as they did
not invade her home.

   According to Hodge, the officers knew that there was no
way out of the room other than the door they were guarding
28    SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

and that there were no other occupants in the building, facts
that distinguish this case from those in which officers’ more
confrontational tactics were held to be reasonable based on
the need to protect others. See, e.g., Reynolds, 84 F.3d at
1168 (“Reynolds was not in a confined area and there were
other people in the vicinity.”); Estate of Bennett v.
Wainwright, 548 F.3d 155, 169 (1st Cir. 2008) (“[A]
reasonable officer under the circumstances could have
reasonably believed . . . that entering the house without first
obtaining a warrant or express consent was necessary to
prevent injury to Bennett himself, and to the family members
present inside.”), overruled on other grounds by Maldonado
v. Fontanes, 568 F.3d 263, 269 (1st Cir. 2009); Black,
482 F.3d at 1039 (“The police were justified in their entry
because they feared that [a domestic violence victim] could
have been inside the apartment, badly injured and in need of
medical attention . . . .”); Ewolski v. City of Brunswick,
287 F.3d 492, 502 (6th Cir. 2002) (the subject’s “dramatic
reaction” to police, “combined with the officers’ knowledge
that he was armed and volatile and that his wife and child
were in the house with him, reveals an undisputed body of
evidence from which a reasonable officer could have
reasonably concluded that there was an immediate threat to
[the subject’s] wife and son”). Sheehan, with some force,
argues that whatever her behavior in resisting unwanted
medical assistance and claiming the sanctity of her home,
once the officers exited her room and her door was shut the
threats to the safety of the officers or others were under
control and there was no need to force a confrontation. Of
significance, all of the information known to the officers
suggested that Sheehan wanted only to be left alone in her
home. She had shown no desire to leave the room. Although
she had acted in a threatening manner, she had done so only
to those who had entered her home without her permission.
      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO              29

The officers also were aware that Sheehan, who they knew
was both mentally ill and emotionally disturbed, was not
likely to respond rationally to police officers breaking down
her door. A rational person, recognizing that she was
outnumbered and facing superior firepower, might have been
expected to drop the knife and surrender. As the officers
knew, however, Sheehan was mentally ill and acting
irrationally, and, given her initial reaction to the officers,
likely to react violently to an escalating show of force. As we
explained in Deorle v. Rutherford, 272 F.3d 1272 (9th Cir.
2001), the tactics to be employed against an

       emotionally distraught individual who is
       creating a disturbance or resisting arrest are
       ordinarily different from those involved in
       law enforcement efforts to subdue an armed
       and dangerous criminal who has recently
       committed a serious offense. In the former
       instance, increasing the use of force may, in
       some circumstances at least, exacerbate the
       situation; in the latter, a heightened use of
       less-than-lethal force will usually be helpful
       in bringing a dangerous situation to a swift
       end.

Id. at 1282–83; see also Glenn, 673 F.3d at 875 (“Another
circumstance relevant to our analysis is whether the officers
were or should have been aware that Lukus was emotionally
disturbed.”); Drummond ex rel. Drummond v. City of
Anaheim, 343 F.3d 1052, 1058 (9th Cir. 2003) (if “it is or
should be apparent to the officers that the individual involved
is emotionally disturbed, that is a factor that must be
considered in determining, under Graham, the reasonableness
30     SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

of the force employed” (quoting Deorle, 272 F.3d at 1283)).10
The officers’ decision to force an entry was in effect a
decision to cause a violent – and potentially deadly –
confrontation with a mentally ill person without a
countervailing need. Thus, on this record, we cannot say as
a matter of law that the officers conducted the search or
seizure in a reasonable manner or used appropriate force by
forcing their way back into Sheehan’s home.

    Of course, a reasonable jury could find that the officers
acted reasonably by forcing the entry. Whether Sheehan was
contained, the officers had reason to fear Sheehan’s escape,
the officers knew the building was empty and the officers
could have ensured their safety by retreating are all disputed
facts that a jury could resolve in the officers’ favor. To find
the officers liable, moreover, the jury would have to conclude
not only that freezing or attempting to de-escalate the
situation were reasonable courses of action but also that
forcing an entry was unreasonable. See Glenn, 673 F.3d at
876 (explaining that police officers “need not avail
themselves of the least intrusive means of responding to an
exigent situation” and that “they need only act within that
range of conduct we identify as reasonable” (quoting Scott,
39 F.3d at 915) (internal quotation marks omitted)). Viewing
the evidence favorably to Sheehan, however, we cannot say
that the officers acted reasonably as a matter of law.

                                  3.

   Having determined that a reasonable jury could find a
Fourth Amendment violation, we next consider whether the

 10
    In contrast to Deorle, Sheehan was armed. But she was also contained
(or so a reasonable jury could find), so Deorle remains relevant.
      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO              31

officers are nonetheless entitled to qualified immunity. At
this stage of the proceedings, the operative question is
whether, again viewing the facts in the light most favorable
to Sheehan, the officers violated a clearly established Fourth
Amendment right of which all but the plainly incompetent
would have been aware. See Stanton v. Sims, 134 S. Ct. 3, 5
(2013) (per curiam).

    As noted, determining whether the force used to effect a
particular search or seizure is reasonable under the Fourth
Amendment requires 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. See Graham, 490 U.S. at 396. Put
differently, we “balance the amount of force applied against
the need for that force.” Meredith v. Erath, 342 F.3d 1057,
1061 (9th Cir. 2003). Construing the facts favorably to
Sheehan, the officers’ intrusion on Sheehan’s Fourth
Amendment rights was profound – the officers forced an
entry into her home, apparently without warning and with
guns drawn, under conditions that were likely to result in her
death. On the other side of the equation, the governmental
interest in the intrusion was minimal because she was fully
contained, not a flight risk and not a danger to the safety of
the officers or others; backup was on the way; and trained
negotiators could have been used to defuse the crisis. If there
was no pressing need to rush in, and every reason to expect
that doing so would result in Sheehan’s death or serious
injury, then any reasonable officer would have known that
this use of force was excessive. See Deorle, 272 F.3d at
1281–85 (holding that the use of nonlethal force was
excessive when the officers had a clear line of retreat and
“could easily have avoided a confrontation, and awaited the
arrival of a negotiating team”).
32    SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

     Our decision in Alexander v. City & County of San
Francisco, 29 F.3d 1355 (9th Cir. 1994), is instructive.
There, police were present outside the decedent Quade’s
home to assist in executing an administrative forcible entry
warrant permitting local health officials to inspect the home
for a sewage leak. See id. at 1358. Quade refused to let the
inspectors in and threatened to shoot anyone who entered.
See id. The officers cordoned off the area, attempted to
negotiate a peaceful resolution of the standoff for an hour and
then forcibly entered the home. See id. When the officers
entered, Quade pointed and fired a gun at the officers, who
returned fire, shooting and killing him. See id. The plaintiff
(Quade’s executor) alleged that the officers used excessive
force, challenging not the shooting itself but rather the force
the officers used in entering the house. See id. at 1366 &
n.12. We denied summary judgment to the defendants both
on the merits and on their qualified immunity defense. See
id. at 1366–67. We held that the plaintiff’s claim “that it was
unreasonable for the officers to storm the house of a man
whom they knew to be a mentally ill, elderly, half-blind
recluse who had threatened to shoot anybody who entered”
stated “a classic Fourth Amendment violation under
Graham.” Id. at 1366. We said that, if the jury were to find
that the officers stormed the house to carry out the health
inspection, “then the jury may also conclude that the force
used . . . was excessive in relation to the purpose for which it
was used.” Id. at 1367.

   Alexander and this case have much in common. In both
cases, police officers had a legal right to enter a person’s
home (to render emergency aid in Sheehan’s case and to
execute an administrative warrant in Alexander). In both
cases, the subject was contained and had threatened those
who entered. In both, the officers knew they were dealing
        SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO                         33

with someone who was mentally ill and acting irrationally.
And in both, police officers decided to force an entry,
knowing it was likely to result in a violent confrontation,
absent the need to do so. Indeed, the facts here are in one
respect even more troubling than those in Alexander. The
officers radioed for reinforcements in both cases, but only in
Alexander did the officers wait for backup to arrive and at
least attempt negotiation before storming in.11

    Although the facts of Alexander are not identical to those
of this case, Graham, Alexander and Deorle would have
placed any reasonable, competent officer on notice that it is
unreasonable to forcibly enter the home of an armed,
mentally ill subject who had been acting irrationally and had
threatened anyone who entered when there was no objective
need for immediate entry. We emphasize that at trial the
facts may show that Sheehan was not contained, that she
presented a flight risk, that officers or others were in danger,
or that the officers reasonably but mistakenly believed that
their entry was necessary to prevent Sheehan’s escape or
ensure the safety of themselves or others. The facts,
however, are disputed, and it would be premature to hold at
this stage of the proceedings that the officers are – as a matter



   11
      We acknowledge that Alexander has been limited by subsequent
circuit precedent to the extent it informs our provocation doctrine – the
principle discussed in part I.C of this opinion that an officer may be liable
for an otherwise reasonable use of deadly force when the officer has
intentionally or recklessly provoked the deadly confrontation. See George
v. Morris, 736 F.3d 829, 839 n.14 (9th Cir. 2013); Billington, 292 F.3d at
1188–91. Those cases are inapplicable here, however, where the issue at
this point is not whether the shooting violated the Fourth Amendment (on
a provocation theory) but rather whether the officers’ antecedent forcible
entry did.
34      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

of law – entitled to qualified immunity. See Glenn, 673 F.3d
at 870 & n.7; Alexander, 29 F.3d at 1366–67.12

                           C. Deadly Force

    We turn, then, to the officers’ use of deadly force. “[A]n
officer’s use of deadly force is reasonable if ‘the officer has
probable cause to believe that the suspect poses a significant
threat of death or serious physical injury to the officer or
others.’” Reynolds, 84 F.3d at 1167 (quoting Tennessee v.
Garner, 471 U.S. 1, 3 (1985)). “Thus, where a suspect
threatens an officer with a weapon such as a gun or a knife,
the officer is justified in using deadly force.” Smith v. City of
Hemet, 394 F.3d 689, 704 (9th Cir. 2005) (en banc).

    Here, the officers’ use of deadly force – viewed from the
standpoint of the moment of the shooting – was reasonable as
a matter of law. Although the parties disagree over the details
surrounding the shooting, the material facts are undisputed:
Sheehan had threatened to kill the officers, she wielded a
knife in an upraised position, she advanced toward the
officers, she did not drop the knife after being pepper sprayed
(or even after being shot) and the shooting took place while
Sheehan was only a few feet from a cornered Officer Holder.
Although Sheehan insists that she was blinded and disabled
by the pepper spray, she indisputably continued to hold the
knife and advance toward the officers, in cramped quarters,


 12
    If Sheehan is able to establish that the second entry violated the Fourth
Amendment (and the officers are not entitled to qualified immunity), then
she can recover damages proximately caused by the violation. See
Jackson v. Gates, 975 F.2d 648, 655 (9th Cir. 1992) (“Under § 1983
Jackson was entitled to sue for all consequential damages resulting from
the violation of his Fourth Amendment rights.”).
      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO               35

after being sprayed. Thus, even if Sheehan in fact was not
intending to attack the officers at that point in the
confrontation, the officers reasonably believed they were still
in danger. At the moment of the shooting, the defensive use
of deadly force, although unfortunate, did not violate the
Fourth Amendment.

    We must also consider whether the shooting was
reasonable when the events leading up to the shooting are
taken into account. As previously discussed, “where an
officer intentionally or recklessly provokes a violent
confrontation, if the provocation is an independent Fourth
Amendment violation, he may be held liable for his otherwise
defensive use of deadly force.” Billington, 292 F.3d at 1189
(emphasis added). Here, Sheehan has presented a triable
issue as to whether the officers committed an independent
Fourth Amendment violation by their forcible second entry
into her room, as discussed above. In addition, Sheehan has
presented evidence from which a reasonable jury could find
that the officers acted recklessly in failing to take Sheehan’s
mental illness into account and in forcing a deadly
confrontation rather than freezing or attempting to de-escalate
the situation. We therefore hold that there are triable issues
of fact as to whether the shooting was unreasonable on a
provocation theory.

    Finally, we address Sheehan’s claim that Sergeant
Reynolds’ final shot amounted to excessive force. Assuming,
as we must, that Sheehan had already reached the ground
when Reynolds fired the final shot, we nonetheless hold that
Reynolds is entitled to qualified immunity. Even if Reynolds
continued to fire after Sheehan reached the ground, “it is clear
from the very brief time that elapsed that [Reynolds] made a
split-second judgment in responding to an imminent threat
36    SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

and fired a fusillade in an emergency situation.” Berube v.
Conley, 506 F.3d 79, 85 (1st Cir. 2007). Reynolds’ actions
“cannot be found unreasonable because she may have failed
to perfectly calibrate the amount of force required to protect
herself.” Id. Even if Sheehan was on the ground, she was
certainly not subdued, and she continued to hold a knife and
threaten the officers, especially Holder, who was cornered
and in close proximity to Sheehan. Sheehan has presented no
authority holding that the use of deadly force under similar
circumstances was excessive. Thus, Reynolds is entitled to
qualified immunity on this basis.

                  II. MONELL CLAIMS

   Sheehan asserted § 1983 claims against the city under
Monell v. Department of Social Services of the City of New
York, 436 U.S. 658 (1978). She raises two theories of
municipal liability: (1) failure to train and (2) ratification.
We hold that the district court properly granted summary
judgment to the city on each of these claims.

                    A. Failure to Train

    “The ‘inadequacy of police training may serve as the
basis for § 1983 liability only where the failure to train
amounts to deliberate indifference to the rights of persons
with whom the police come into contact.’” Price v. Sery,
513 F.3d 962, 973 (9th Cir. 2008) (quoting City of Canton v.
Harris, 489 U.S. 378, 388 (1989)). Here, Reynolds
acknowledges that she did not take Sheehan’s mental illness
into account when she ordered the second entry into
Sheehan’s room. Sheehan, however, has not pointed to
anything in the record to suggest that Reynolds’ training was
responsible for her decision to disregard Sheehan’s mental
      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO              37

illness. On the contrary, Sheehan concedes that the
department employed appropriate training materials to guide
police officers’ responses to persons they knew to be
suffering from mental illness. That Reynolds may have
disregarded her training does not show that the city was
deliberately indifferent.

                      B. Ratification

     Sheehan’s ratification theory also fails. “To show
ratification, a plaintiff must prove that the ‘authorized
policymakers approve a subordinate’s decision and the basis
for it.’” Christie v. Iopa, 176 F.3d 1231, 1239 (9th Cir. 1999)
(quoting City of St. Louis v. Praprotnik, 485 U.S. 112, 127
(1988)). “We have found municipal liability on the basis of
ratification when the officials involved adopted and expressly
approved of the acts of others who caused the constitutional
violation.” Trevino v. Gates, 99 F.3d 911, 920 (9th Cir.
1996).

     Sheehan contends that the city ratified the officers’
conduct by not disciplining them. Ratification, however,
generally requires more than acquiescence. There is no
evidence in the record that policymakers “made a deliberate
choice to endorse” the officers’ actions. Gillette v. Delmore,
979 F.2d 1342, 1348 (9th Cir. 1992). The mere failure to
discipline Reynolds and Holder does not amount to
ratification of their allegedly unconstitutional actions. See
Clouthier v. Cnty. of Contra Costa, 591 F.3d 1232, 1253–54
(9th Cir. 2010) (holding that the failure to discipline
employees, without more, was insufficient to establish
ratification); Santiago v. Fenton, 891 F.2d 373, 382 (1st Cir.
1989) (refusing to hold that the “failure of a police
38    SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

department to discipline in a specific instance is an adequate
basis for municipal liability under Monell”).

     III. AMERICANS WITH DISABILITIES ACT

    We next address Sheehan’s claim that the city violated
her rights under the Americans with Disabilities Act (ADA).

    Title II of the ADA provides that “no qualified individual
with a disability shall, by reason of such disability, be
excluded from participation in or be denied the benefits of the
services, programs, or activities of a public entity, or be
subjected to discrimination by any such entity.” 42 U.S.C.
§ 12132. Discrimination includes a failure to reasonably
accommodate a person’s disability. As United States
Department of Justice regulations state:

       A public entity shall make reasonable
       modifications in policies, practices, or
       procedures when the modifications are
       necessary to avoid discrimination on the basis
       of disability, unless the public entity can
       demonstrate that making the modifications
       would fundamentally alter the nature of the
       service, program, or activity.

28 C.F.R. § 35.130(b)(7).

    We have not previously addressed whether the ADA
applies to arrests, see Thompson v. Davis, 295 F.3d 890, 897
(9th Cir. 2002), and the question is a matter of some
disagreement among other circuits. The Fifth Circuit has held
that “Title II does not apply to an officer’s on-the-street
responses to reported disturbances or other similar incidents,
      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO              39

whether or not those calls involve subjects with mental
disabilities, prior to the officer’s securing the scene and
ensuring that there is no threat to human life.” Hainze v.
Richards, 207 F.3d 795, 801 (5th Cir. 2000). Other circuits
have declined to adopt the Fifth Circuit’s approach. In
Bircoll v. Miami-Dade County, 480 F.3d 1072 (11th Cir.
2007), the Eleventh Circuit held that “the question is not so
much one of the applicability of the ADA because Title II
prohibits discrimination by a public entity by reason of [a
person’s] disability. The exigent circumstances presented by
criminal activity and the already onerous tasks of police on
the scene go more to the reasonableness of the requested
ADA modification than whether the ADA applies in the first
instance.” Id. at 1085. Similarly, in Gohier v. Enright,
186 F.3d 1216 (10th Cir. 1999), the Tenth Circuit held that “a
broad rule categorically excluding arrests from the scope of
Title II . . . is not the law.” Id. at 1221. In Waller ex rel.
Estate of Hunt v. City of Danville, 556 F.3d 171, 175 (4th Cir.
2009), the Fourth Circuit reserved judgment on the Fifth
Circuit’s approach and then went on to consider a reasonable
accommodation claim involving an arrest. Like the Eleventh
Circuit, Waller held that “exigency is one circumstance that
bears materially on the inquiry into reasonableness under the
ADA.” Id. See also Tucker v. Tennessee, 539 F.3d 526, 534
(6th Cir. 2008) (addressing a Title II reasonable
accommodation claim in which the plaintiffs asserted that
police officers “discriminated against them in violation of the
ADA by failing to provide a qualified sign language
interpreter or other such reasonable accommodation(s) during
the domestic disturbance call that resulted in their arrest”).

    We agree with the majority of circuits to have addressed
the question that Title II applies to arrests. The ADA applies
broadly to police “services, programs, or activities.”
40    SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

42 U.S.C. § 12132. We have interpreted these terms to
encompass “anything a public entity does.” Barden v. City of
Sacramento, 292 F.3d 1073, 1076 (9th Cir. 2002) (quoting
Lee v. City of Los Angeles, 250 F.3d 668, 691 (9th Cir. 2001))
(internal quotation marks omitted). The ADA therefore
applies to arrests, though we agree with the Eleventh and
Fourth Circuits that exigent circumstances inform the
reasonableness analysis under the ADA, just as they inform
the distinct reasonableness analysis under the Fourth
Amendment. See Waller, 556 F.3d at 175 (“Just as the
constraints of time figure in what is required of police under
the Fourth Amendment, they bear on what is reasonable
under the ADA.”).

    Courts have recognized at least two types of Title II
claims applicable to arrests: (1) wrongful arrest, where police
wrongly arrest someone with a disability because they
misperceive the effects of that disability as criminal activity;
and (2) reasonable accommodation, where, although police
properly investigate and arrest a person with a disability for
a crime unrelated to that disability, they fail to reasonably
accommodate the person’s disability in the course of
investigation or arrest, causing the person to suffer greater
injury or indignity in that process than other arrestees. See
Waller, 556 F.3d at 174; Gohier, 186 F.3d at 1220-21.

    Sheehan raises the second type of claim here. She asserts
that the officers failed to reasonably accommodate her
disability by forcing their way back into her room without
taking her mental illness into account and without employing
tactics that would have been likely to resolve the situation
without injury to herself or others. To state a claim under
Title II of the ADA, a plaintiff generally must show: (1) she
is an individual with a disability; (2) she is otherwise
      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO               41

qualified to participate in or receive the benefit of a public
entity’s services, programs or activities; (3) she was either
excluded from participation in or denied the benefits of the
public entity’s services, programs or activities or was
otherwise discriminated against by the public entity; and
(4) such exclusion, denial of benefits or discrimination was
by reason of her disability. See O’Guinn v. Lovelock Corr.
Ctr., 502 F.3d 1056, 1060 (9th Cir. 2007). In a Title II claim
grounded in a public entity’s alleged failure to provide a
reasonable accommodation under 28 C.F.R. § 35.130(b)(7),
the plaintiff bears the initial burden of producing evidence of
the existence of a reasonable accommodation. See Vinson v.
Thomas, 288 F.3d 1145, 1154 (9th Cir. 2002). A public
entity may defeat a reasonable accommodation claim by
showing “that making the modifications would fundamentally
alter the nature of the service, program, or activity.”
28 C.F.R. § 35.130(b)(7); see Zukle v. Regents of Univ. of
Cal., 166 F.3d 1041, 1047 (9th Cir. 1999).

     It is undisputed that Sheehan had a disability and that the
officers knew it at the time they encountered her. We turn,
therefore, to whether the city discriminated against Sheehan
by failing to provide a reasonable accommodation during the
second entry. Sheehan asserts that the city failed to provide
a reasonable accommodation when the officers forced their
way back into her room without taking her mental illness
into account. She asserts that the officers should have
respected her comfort zone, engaged in non-threatening
communications and used the passage of time to defuse the
situation rather than precipitating a deadly confrontation. We
acknowledge that the officers were forced to make split-
second decisions. A reasonable jury nevertheless could find
that the situation had been defused sufficiently, following the
initial retreat from Sheehan’s room, to afford the officers an
42    SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

opportunity to wait for backup and to employ less
confrontational tactics, including the accommodations that
Sheehan asserts were necessary. For the reasons stated here,
and because the reasonableness of an accommodation is
ordinarily a question of fact, see EEOC v. UPS Supply Chain
Solutions, 620 F.3d 1103, 1110 (9th Cir. 2010), we hold that
the city is not entitled to judgment as a matter of law on
Sheehan’s ADA claim.

               IV. STATE LAW CLAIMS

    Sheehan asserts state law claims for negligence, assault
and battery, intentional infliction of emotional distress and
violation of California Civil Code § 52.1. The district court
ruled that the defendants are immune from liability on those
claims under California Welfare & Institutions Code § 5278,
which provides: “Individuals authorized under this part to
detain a person for 72-hour treatment and evaluation . . . shall
not be held either criminally or civilly liable for exercising
this authority in accordance with the law.”

    In Bias v. Moynihan, 508 F.3d 1212, 1221 (9th Cir. 2007),
we held that a police officer was immune under § 5278 from
state law claims for assault and battery, false arrest, illegal
imprisonment and intentional infliction of emotional distress
where the officer had probable cause to take the plaintiff into
custody in accordance with § 5150. The scope of § 5278
immunity, however, is not as all-encompassing as the
defendants argue. Section 5278 is part of the Lanterman-
Petris-Short Act, which must be construed to protect mentally
disordered persons. See Gonzalez v. Paradise Valley Hosp.,
3 Cal. Rptr. 3d 903, 907 (Ct. App. 2003). In Jacobs v.
Grossmont Hospital, 133 Cal. Rptr. 2d 9 (Ct. App. 2003), the
California Court of Appeal held that
      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO              43

       the immunity of section 5278 extends to
       claims based on circumstances that are
       inherent in an involuntary detention pursuant
       to section 5150. Without the immunity
       provided by section 5278, an involuntary
       detention and treatment without consent
       would arguably constitute kidnapping, false
       imprisonment, or battery. Section 5278 was
       intended to provide immunity for claims
       based on conduct that is expressly authorized
       by the LPS Act but would otherwise constitute
       a civil or criminal wrong. . . . [A] plaintiff
       who is properly detained in accordance with
       the LPS Act may not assert any civil claim
       based solely on the fact that he was detained,
       evaluated, or treated without his consent [but]
       section 5278 [does not] confer blanket
       immunity for any act or omission that might
       occur during a 72-hour hold, no matter how
       negligent, wrongful, or even criminal.

Id. at 15 (emphasis added).

     Thus, § 5278 immunizes the police officers from the
decision to detain Sheehan under § 5150. Section 5278 also
immunizes the officers from liability for the fact of Sheehan’s
detention. Finally, § 5278 immunizes the officers based on
circumstances inherent in her involuntary detention. See id.
at 16. Section 5278, however, does not immunize the officers
if they were negligent in executing the detention. Any injury
Sheehan suffered from the officers’ failure to exercise
ordinary care in taking Sheehan into custody would not be an
“inherent attribute[]” of her detention and therefore would not
44    SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

be subject to § 5278 immunity. Id. Bias does not hold to the
contrary.

    The district court therefore erred by granting summary
judgment to the defendants under § 5278. The defendants
argue that they are entitled to immunity under several other
statutes. See Cal. Gov’t Code § 821.6; Cal. Penal Code
§§ 196, 836.5, 835a, 847(b). Although we may affirm on any
ground supported by the record, we decline to address the
defendants’ alternative arguments because they have not been
passed upon by the district court. We therefore vacate the
dismissal of these claims and remand to the district court.

                      CONCLUSION

    The district court properly granted summary judgment to
the defendants on Sheehan’s warrantless entry Fourth
Amendment claims and on her Monell claims against the city.
The district court erred by granting summary judgment on
Sheehan’s Fourth Amendment claims challenging the manner
of the second entry and the use of deadly force and on her
ADA and state law claims. We therefore affirm the judgment
in part, vacate it in part and remand for further proceedings.
Each party shall bear its own costs on appeal.

  AFFIRMED IN PART, VACATED IN PART AND
REMANDED.
      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO               45

GRABER, Circuit Judge, concurring in part and dissenting in
part:

    Although I agree with the remainder of the opinion, I
respectfully dissent from the majority’s decision on the
Fourth Amendment excessive force claim with respect to the
second entry into Plaintiff’s apartment. Whether that second
entry is viewed as a separate search or, instead, as part of one
continuous search, the officers are entitled to qualified
immunity even when taking all facts in the summary
judgment record in Plaintiff’s favor. Accordingly, I would
affirm the summary judgment in favor of Defendants on that
claim.

   A. If the Second Entry Is a Separate Search

     The second entry met an exception to the warrant
requirement—the emergency aid doctrine or the exigent
circumstances doctrine or both. Plaintiff was off her
psychotropic medications, was not taking care of herself, and
was making violent threats toward other people. Upon the
first entry, which the majority agrees was lawful under the
Fourth Amendment, Plaintiff had threatened to kill the
officers while wielding a knife. Defendants did not know
whether Plaintiff could escape from the apartment by another
route, such as a window, or whether she had access to
additional weapons, such as firearms, in either event creating
the immediate possibility of harm to the officers, Plaintiff,
and others. Accordingly, as the majority holds, the officers
could enter the apartment for the second time without
violating the warrant requirement of the Fourth Amendment.

   As to the method of effecting the second entry,
Defendants determinedly pushed the door open while holding
46     SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

pepper spray and a service weapon. In light of the danger
posed by Plaintiff, who held a knife and had threatened to kill
the officers, the officers reasonably could conclude that
entering the apartment in that way would not violate the
Fourth Amendment’s prohibition on the use of excessive
force.

    The expert’s report that faulted the officers for electing to
enter Plaintiff’s apartment when and as they did does not
create an issue of fact on either the timing or the method of
the second entry. As we have cautioned, a plaintiff cannot
avoid summary judgment merely by producing an expert’s
report opining that an officer’s conduct was imprudent or
inappropriate:

            We have since placed important
        limitations on Alexander [v. City of San
        Francisco, 29 F.3d 1355 (9th Cir. 1994)]. In
        Scott v. Henrich, [39 F.3d 912, 915 (9th Cir.
        1994)], we held that even though the officers
        might have had “less intrusive alternatives
        available to them,” and perhaps under
        departmental guidelines should have
        “developed a tactical plan” instead of
        attempting an immediate seizure, police
        officers “need not avail themselves of the
        least intrusive means of responding” and need
        only act “within that range of conduct we
        identify as reasonable.” We reinforced this
        point in Reynolds v. County of San Diego,
        [84 F.3d 1162, 1169 (9th Cir. 1996),] which
        distinguished Alexander because “the court
        must allow for the fact that officers are forced
        to make split second decisions.” We affirmed
      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO               47

       summary judgment for the defendant police
       officers despite experts’ reports stating—like
       the expert report in the case at bar—that the
       officers should have called and waited for
       backup, rather than taking immediate action
       that led to deadly combat. [Id. at 1169–70.]
       We held that, even for summary judgment
       purposes, “the fact that an expert disagrees
       with the officer’s actions does not render the
       officer’s actions unreasonable.” [Id. at 1170.]
       Together, Scott and Reynolds prevent a
       plaintiff from avoiding summary judgment by
       simply producing an expert’s report that an
       officer’s conduct leading up to a deadly
       confrontation was imprudent, inappropriate,
       or even reckless. [Id.] Rather, the court must
       decide as a matter of law “whether a
       reasonable officer could have believed that his
       conduct was justified.” [Id.]

Billington v. Smith, 292 F.3d 1177, 1188–89 (9th Cir. 2002)
(footnotes omitted).

   B. If the Second Entry Is Part of a Continuous Search

    The first and second entries may, in the alternative, be
considered part of a single, continuous search. Insofar as the
exigent circumstances that justified the first entry were
ongoing, the second entry was justified under the emergency
aid exception.

    When the officers retreated from Plaintiff’s apartment
after she had threatened them with a knife upon their initial
entry, they had confirmation that Plaintiff in fact had a deadly
48    SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO

weapon and appeared willing to use it. That is, Plaintiff’s
behavior toward the officers during their initial entry only
confirmed that her condition had deteriorated to the point of
creating an emergency. She was now out of sight behind
closed doors, where additional weapons, including firearms,
could have been present. It was objectively reasonable,
therefore, for the officers to believe that Plaintiff was even
more of a danger to herself and to others than they had
assumed before the first entry. Here, as in Michigan v. Tyler,
436 U.S. 599, 511 (1978), and Fisher v. City of San Jose,
558 F.3d 1069, 1077 (9th Cir. 2009) (en banc), the passage of
time was brief and the exigent circumstances that motivated
the first entry “did not materially change from the beginning
of the standoff to the end.” Because the exigency persisted or
worsened throughout, “the officers were not required to
periodically reassess whether the exigency persisted
throughout the standoff because the standoff was ‘no more
than an actual continuation’ of the initial seizure.” Fisher,
558 F.3d at 1077 (quoting Tyler, 436 U.S. at 511).

    I would hold that reasonable officers could have
concluded that they were entitled to continue the initial search
and that determinedly pushing the door open with weapons
readied was a reasonable amount of force when balanced
against the need to resolve an ongoing emergency that
involved a deadly weapon. See Billington, 292 F.3d at 1184
(“We analyze excessive force claims in the arrest context
under the Fourth Amendment’s reasonableness standard. We
balance ‘the nature and quality of the intrusion on the
individual’s Fourth Amendment interests against the
countervailing governmental interests at stake’ and ask
whether, under the circumstances, ‘including the severity of
the crime at issue, the suspect poses an immediate threat to
the safety of the officers or others . . .’” (quoting Graham v.
      SHEEHAN V. CITY & CNTY. OF SAN FRANCISCO               49

Connor, 490 U.S. 386, 395–96 (1989)). In view of the extant
legal principles, reasonable officers could conclude that their
actions were permitted even though Plaintiff suffered from a
mental illness. Police officers often interact with individuals
who have a wide variety of specific needs, and there is no
controlling case law that requires a different Fourth
Amendment analysis for an officer on the street who faces
those circumstances. See Deorle v. Rutherford, 272 F.3d
1272, 1283 (9th Cir. 2001) (“We do not adopt a per se rule
[for excessive force] establishing two different classifications
of suspects:       mentally disabled persons and serious
criminals.”). Moreover, we must “judge reasonableness
‘from the perspective of a reasonable officer on the scene,
rather than with the 20/20 vision of hindsight’ and allow ‘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.’” Billington, 292 F.3d at
1184 (quoting Graham, 490 U.S. at 396).

   C. Conclusion

    The district court properly granted summary judgment to
Defendants on the Fourth Amendment excessive force claim
concerning the second entry into Plaintiff’s apartment.
Defendants are entitled to qualified immunity. I therefore
respectfully dissent from the majority’s contrary holding on
that claim, but otherwise concur.
