United States Court of Appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT



Argued January 20, 2012                  Decided July 13, 2012

                         No. 11-7037

                   PAUL DOUGLAS BURKE,
                        APPELLANT

                               v.

           AIR SERV INTERNATIONAL, INC., ET AL.,
                        APPELLEES


         Appeal from the United States District Court
                 for the District of Columbia
                     (No. 1:07-cv-02335)


    David E.R. Woolley argued the cause and filed the briefs for
appellant. Malcolm L. Benge entered an appearance.

     Frank A. Silane argued the cause for appellees. With him
on the brief were Richard A. Lazenby, Ivy L. Nowinski, Thomas
J. Whalen, Edward J. Longosz II, Mark A. Johnston, and Daniel
A. Glass.

    Before: HENDERSON, GARLAND, and BROWN, Circuit
Judges.

    Opinion for the Court filed by Circuit Judge GARLAND.
                                2

     GARLAND, Circuit Judge: Plaintiff Paul Burke, a former
British soldier, was severely wounded in an ambush in
Afghanistan, where he was working for a private security
contractor. Burke sued the transport company that furnished the
helicopter he flew in on and the construction company that
contracted with his employer for his security services, alleging
that they had negligently failed to take appropriate security
measures for his trip. The district court granted summary
judgment for the defendants because Burke failed to proffer --
as District of Columbia law requires -- an expert to testify
regarding the standard of care for such security precautions.

     On appeal, Burke maintains that no expert was required
because, inter alia, “every juror will have seen” such films as
High Noon. Burke Br. 31. Perhaps. But even if they have, we
are puzzled about what they could have learned from those films
that would have been helpful to Burke’s case. After all, Marshal
Kane (Gary Cooper) did not helicopter to his confrontation with
the Miller gang. Nor did he carry, as Burke did, a 9-mm. pistol
and AK-47 assault rifle. No, Kane walked to the fateful
encounter protected only by two revolvers and a tin star.
Moreover, he did so notwithstanding that the meeting could
hardly have been regarded as an ambush: as the film’s title
makes clear, each side knew precisely what time the showdown
would take place.

     We respect Burke’s long military career and greatly regret
the injuries suffered in the ambush, as well as the death of the
helicopter pilot. But Burke’s reliance on old Westerns rather
than expert testimony to establish the standard of care is “fatal
to [his] negligence claim.” Briggs v. Washington Metro. Area
Transit Auth., 481 F.3d 839, 848 (D.C. Cir. 2007) (internal
quotation marks omitted). Finally -- and more prosaically -- the
Erie doctrine is fatal to his alternative contention that we should
disregard D.C.’s expert testimony requirement altogether.
                                3

                                I

    Burke served in the British military for almost 23 years. He
then became a security consultant for the United Nations World
Food Programme in Afghanistan before accepting a riskier job
for a private security contractor, U.S. Protections and
Investigations (USPI), at almost twice the pay. The Louis
Berger Group (LBG), one of the defendants, was a construction
management company overseeing various projects in
Afghanistan, and it hired USPI to provide security. LBG
engaged the other defendant -- Air Serv International, Inc. -- to
provide helicopter transport to its work sites.

     During his time in Afghanistan, Burke had been ambushed
“lots of times.” Burke Dep. at 271-72 (Feb. 24, 2009). Indeed,
just prior to the ambush giving rise to this case, he authored a
memorandum describing the “tenuous” security situation in
Afghanistan and the recent increase in Taliban attacks against
non-governmental organizations. Paul Burke, USPI SC’s
Briefing for Schools and Clinics at 1 (J.A. 228). As Burke
explained in his deposition, he was specifically concerned about
“opportunist[ic] threat[s]” from the Taliban -- that is, unplanned
attacks like the ambush at the center of this case. Burke Dep. at
129. Burke had also flown in Air Serv helicopters several times
and was aware that they were not armored. Id. at 115.

     Nonetheless, on February 22, 2004, Burke helicoptered to
the village of Taluqan with an engineer and an interpreter to
survey the progress of an LBG project. Burke, who was
equipped with a 9-mm. pistol and AK-47 assault rifle, patrolled
the area around the helicopter while others inspected the
building site. As the party prepared to leave, unknown attackers
opened fire. Burke and the others returned fire and radioed for
help. The firing lasted about thirty minutes. Burke was shot
five times; the pilot was killed; and the engineer was badly
                                   4

wounded. The interpreter was able to call by satellite telephone
for help, which arrived roughly an hour after the attack began.

     In December 2007, Burke filed this action against LBG and
Air Serv, invoking the diversity jurisdiction of the United States
District Court. Burke alleged that both defendants were
negligent in the security procedures they followed and the
security equipment they provided, see Compl. ¶¶ 50-57, and that
LBG was negligent in hiring and retaining his employer, USPI,
to provide security for the aircraft and personnel, id. ¶¶ 58-70.1
He did not, however, sue his employer. After discovery, the
district court granted summary judgment for the defendants on
two alternative grounds: that Burke had assumed the risk of his
injuries, and that Burke had failed to proffer expert testimony
regarding the standard of care owed to him by the defendants as
required by District of Columbia tort law. Burke v. Air Serv
Int’l, Inc., 775 F. Supp. 2d 13, 21, 23 (D.D.C. 2011). Because
the latter ground is sufficient to resolve this appeal, it is the only
ground we discuss below.

                                   II

     Applying the choice-of-law rules of the District of
Columbia to this diversity case, see Klaxon Co. v. Stentor Elec.
Mfg. Co., 313 U.S. 487, 496 (1941), the district court
determined that D.C.’s substantive law governs Burke’s suit.
“Neither party has objected to this choice of law on appeal, and,
finding no apparent error in the District Court’s choice, we shall


     1
      Burke also alleged that LBG and Air Serv were liable for
intentional infliction of emotional distress. See Compl. ¶¶ 71-73.
Because his appellate briefs do not specifically address this claim, let
alone marshal any evidence or legal authority in its support, it is
forfeited. See, e.g., Laurel Bay Health & Rehab. Ctr. v. NLRB, 666
F.3d 1365, 1367 n.2 (D.C. Cir. 2012).
                                5

apply District of Columbia law as well.” BWX Elecs., Inc. v.
Control Data Corp., 929 F.2d 707, 710 (D.C. Cir. 1991).

     In order to prevail on a negligence claim under D.C. law, a
plaintiff “must prove the applicable standard of care, a deviation
from that standard by the defendant, and a causal relationship
between that deviation and the plaintiff’s injury.” Scales v.
District of Columbia, 973 A.2d 722, 730 (D.C. 2009) (internal
quotation marks omitted). Moreover, a plaintiff “‘must put on
expert testimony to establish what the standard of care is if the
subject in question is so distinctly related to some science,
profession or occupation as to be beyond the ken of the average
layperson.’” Briggs, 481 F.3d at 845 (quoting District of
Columbia v. Arnold & Porter, 756 A.2d 427, 433 (D.C. 2000)).
Accordingly, if expert testimony were required to establish the
standard of care here, Burke’s failure to offer such testimony
would justify the grant of summary judgment against him. See
id. at 848 (affirming summary judgment because, under D.C.
law, failure to establish the standard of care is “fatal to a
negligence claim” (internal quotation marks omitted)); see also
Varner v. District of Columbia, 891 A.2d 260, 268-71 (D.C.
2006).

     We agree with the district court that D.C. law requires
expert testimony in this case. Burke alleges that the defendants
were negligent in failing to equip his helicopter with appropriate
radio communications equipment, bulletproof blast mats, and a
bulletproof windshield; in not providing other personnel on the
helicopter with body armor, helmets, and face shields; in not
seeking air clearance permission from the proper authorities
prior to the flight; and in hiring security personnel. Compl.
¶¶ 52-70. But the precise precautions a security contractor
should take in a war zone are plainly “beyond the ken of the
average layperson,” Briggs, 481 F.3d at 845 (internal quotation
marks omitted). As the D.C. Court of Appeals, adopting an old
                                  6

dissenting voice from an analogous Second Circuit case, has
declared: “[C]ourts should not leave it to ‘a jury of tailors and
haberdashers to pass judgment [unaided by expert testimony] on
how to make a wet and rolling deck in a seaway a safe place to
work.’” Beard v. Goodyear Tire & Rubber Co., 587 A.2d 195,
200 (D.C. 1991) (alteration in original) (quoting Zinnel v. U.S.
Shipping Bd. Emergency Fleet Corp., 10 F.2d 47, 49 (2d Cir.
1925) (Hough, J., dissenting)).

     Burke maintains that the standard of care in this case is
“‘within the realm of common knowledge and everyday
experience,’” Godfrey v. Iverson, 559 F.3d 569, 572 (D.C. Cir.
2009) (quoting Arnold & Porter, 756 A.2d at 433). But the D.C.
Court of Appeals has required expert testimony in scenarios far
more familiar to the average juror than an ambush in
Afghanistan.2 And as our court has noted, “expert testimony is
routinely required ‘in negligence cases . . . which involve issues
of safety, security and crime prevention,’” Briggs, 481 F.3d at
845-46 (quoting Varner, 891 A.2d at 267), including allegations
of “negligent ‘hiring, training, and supervision of . . . security
personnel,’” Farooq v. MDRB, Corp., 275 Fed. App’x 11, 12



     2
      See, e.g., Katkish v. District of Columbia, 763 A.2d 703, 706
(D.C. 2000) (maintenance of leaning trees); Scott v. James, 731 A.2d
399, 400 (D.C. 1999) (application of hair relaxer); Tillman v.
Washington Metro. Area Transit Auth., 695 A.2d 94, 97 (D.C. 1997)
(tightness of handcuffs); Messina v. District of Columbia, 663 A.2d
535, 538 (D.C. 1995) (cushioning for the ground underneath
playground monkey bars); Rajabi v. Potomac Elec. Power Co., 650
A.2d 1319, 1322-23 (D.C. 1994) (maintenance of street lights); Toy v.
District of Columbia, 549 A.2d 1, 7 (D.C. 1988) (response when a
prisoner is found hanging in his cell); District of Columbia v.
Freeman, 477 A.2d 713, 719-20 (D.C. 1984) (installation of a
crosswalk -- instead of a stop sign, light, or crossing guard -- at an
intersection).
                                 7

(D.C. Cir. 2008) (quoting Predzin v. DC Arena Ltd. P’ship, No.
02CA 9582, at 5 (D.C. Super. Ct. Oct. 7, 2003)).

     Our decision in Godfrey v. Iverson is not to the contrary.
That case involved a brawl at a D.C. nightclub. In the course of
the brawl, the bodyguard of the defendant basketball star beat up
the plaintiff, who then sued for negligent supervision. We held
that no “expert assistance” was needed to “establish the standard
of care for an individual who is present while his personal
bodyguard, acting on his behalf in clearing a room in a
nightclub, beats a customer and causes significant injuries.” 559
F.3d at 573. Burke attempts to convert this holding into a
broader principle that expert testimony is never needed to
establish the standard of care for supervising security personnel.
But the difference between a barroom brawl and an ambush in
a remote Afghan village is self-evident.

     Finally, Burke insists -- in all seriousness -- that lay jurors
could have intuited the proper standard of care from their
knowledge of old Westerns. “Afghanistan,” he explains, “is
comparable to the old ‘Wild West’ -- lawmen, builders, farmers,
ranchers, schoolteachers, entering savage areas subject to armed
marauders and trying to establish peace, civilization and the rule
of law.” Burke Br. 30-31. Because “[e]very juror will have
seen Gunsmoke or High Noon or the Outlaw Josey Wales or
Lonesome Dove,” every juror will know the proper standard of
care. Id. at 31.

    We do not understand what relevant standard of care jurors
could have gleaned from these Westerns, let alone how it could
have benefited Burke. As to the first point, it seems plain that
films in which the heroes rode horses and carried six-shooters
can tell the jury little about whether helicopters should be
equipped with satellite radios and bulletproof blast mats, or
whether security personnel should be equipped with body armor.
                                   8

As to the second point, we must have seen different versions of
these Westerns than Burke did. In the versions we saw, the
heroes took hardly any special precautions at all before heading
into their confrontations with the outlaws. Will Kane, for
example, set out to meet the fearsome Miller gang with only two
pistols and his marshal’s badge. And as we have noted above,
this was despite his having had time to take whatever other
precautions were available. Frank Miller, after all, was not
arriving until the noon train. See High Noon (Stanley Kramer
Prods. 1952).3

                                   III

     Burke further contends that, even if D.C. law does require
expert testimony in his case, that requirement should not be
applied in a federal court under the Erie doctrine. See Erie R.R.
Co. v. Tompkins, 304 U.S. 64 (1938).4 This circuit has never
expressly addressed that contention. We have, however,
routinely applied D.C.’s expert testimony rule in diversity
cases.5


     3
     Due to the cowardice of the townspeople, however, the
precaution of raising a posse was unavailable to Marshal Kane.
     4
      See Hall v. C & P Tel. Co., 793 F.2d 1354, 1356 (D.C. Cir.
1986) (“It is now well established that this court will apply Erie
principles to the decisions of the District of Columbia Court of
Appeals.”); see also, e.g., Schleier v. Kaiser Found. Health Plan of the
Mid-Atlantic States, Inc., 876 F.2d 174, 180 (D.C. Cir. 1989).
     5
     See, e.g., Capitol Sprinkler Inspection, Inc. v. Guest Servs., Inc.,
630 F.3d 217, 225 (D.C. Cir. 2011); Godfrey, 559 F.3d at 571-72;
Briggs, 481 F.3d at 845; Nat’l Tel. Coop. Ass’n v. Exxon Mobil Corp.,
244 F.3d 153, 154 (D.C. Cir. 2001); Butera v. District of Columbia,
235 F.3d 637, 659 (D.C. Cir. 2001); Daskalea v. District of Columbia,
227 F.3d 433, 445 (D.C. Cir. 2000).
                                 9

     The “broad command of Erie,” of course, is that “federal
courts are to apply state substantive law and federal procedural
law” when sitting pursuant to their diversity jurisdiction. Hanna
v. Plumer, 380 U.S. 460, 465 (1965); see Gasperini v. Ctr. for
Humanities, Inc., 518 U.S. 415, 427 (1996). The Supreme Court
has evolved a set of tests to determine whether a law is
substantive or procedural for Erie purposes. The “first question”
is whether there is a Federal Rule or statute, the “scope” of
which is “sufficiently broad to control the issue before the
Court.” Walker v. Armco Steel Corp., 446 U.S. 740, 749-50
(1980); see Shady Grove Orthopedic Assocs. v. Allstate Ins. Co.,
130 S. Ct. 1431, 1437 (2010); Stewart Org., Inc. v. Ricoh Corp.,
487 U.S. 22, 27 n.6 (1988). If there is, the Federal Rule or
statute governs, state law notwithstanding, “unless it exceeds
statutory authorization or Congress’s rulemaking power.” Shady
Grove, 130 S. Ct. at 1437 (citing Hanna, 380 U.S. at 463-64);
see Gasperini, 518 U.S. at 428 n.7.

     Burke argues that the District’s expert testimony
requirement conflicts with Federal Rule of Evidence 702, and
that the latter must therefore control.6 We disagree. Rule 702
provides:

         A witness who is qualified as an expert by knowledge,
         skill, experience, training, or education may testify in
         the form of an opinion or otherwise if: (a) the expert’s
         scientific, technical, or other specialized knowledge
         will help the trier of fact to understand the evidence or
         to determine a fact in issue; (b) the testimony is based
         on sufficient facts or data; (c) the testimony is the


    6
      Congress adopted the Federal Rules of Evidence by statute in
1975. Pub. L. 93-595, 88 Stat. 1926. The Rules “may be amended as
provided in” the Rules Enabling Act, 28 U.S.C. § 2072. FED. R. EVID.
1102.
                                 10

          product of reliable principles and methods; and (d) the
          expert has reliably applied the principles and methods
          to the facts of the case.

As is apparent, Rule 702 determines the circumstances in which
expert testimony is permitted (i.e., admissible). The District’s
rule, by contrast, defines a circumstance in which expert
testimony is required. A federal court can simultaneously apply
both the federal standard regarding what qualifies as expert
testimony and the District rule regarding when qualified expert
testimony is required. They “can exist side by side, . . . each
controlling its own intended sphere of coverage without
conflict.” Walker, 446 U.S. at 752. Thus, because Rule 702
does not “answer[] the question in dispute” -- whether the
plaintiff is required to proffer expert testimony to satisfy his
burden of proof -- it does not preempt the state rule. Shady
Grove, 130 S. Ct. at 1437.

     Even if Rule 702 does not resolve the issue, Burke
maintains that the District’s rule is unreasonable and that we
should ignore it as a matter of federal common law. But when,
as here, “no federal statute or Rule covers the point in dispute,”
Stewart Org., 487 U.S. at 27 n.6, we must apply state law if it is
“outcome-determinative” in the relevant sense. Hanna, 380
U.S. at 468; see Gasperini, 518 U.S. at 428.7 To make that
determination, we ask whether the failure to enforce state law
“would disserve the so-called ‘twin aims of the Erie rule:
discouragement of forum-shopping and avoidance of inequitable


     7
      The Supreme Court has suggested that the outcome-
determinative test may be “an insufficient guide in cases presenting
countervailing federal interests.” Gasperini, 518 U.S. at 432 (citing
Byrd v. Blue Ridge Rural Elec. Coop., Inc., 356 U.S. 525, 537 (1958)).
Burke has not identified any countervailing federal interest in this
case.
                                   11

administration of the laws.’” Stewart Org., 487 U.S. at 27 n.6
(quoting Hanna, 380 U.S. at 468); see Gasperini, 518 U.S. at
428. The decision whether to apply a state law under Erie must
be made across the board; if Erie commands application of a
state rule, the rule applies in all diversity cases in federal court,
and vice versa. Therefore we do not simply consider whether
application of the District’s expert testimony rule would
encourage forum shopping or be inequitable in this case alone.
That is, whether or not Burke himself might have been able to
find an expert to support his claim is not dispositive.

    With this framework in mind, it is clear that we must apply
D.C.’s requirement of expert testimony because failing to do so
would undermine the twin aims of Erie.8 There will certainly be


     8
      We note that other circuits have applied similar state rules under
Erie. See, e.g., In re Paoli R.R. Yard PCB Litig., 35 F.3d 717, 750-51
(3d Cir. 1994) (holding that a Pennsylvania rule, requiring experts to
testify about causation with a “reasonable degree of medical
certainty,” is “an element of [the] plaintiff’s burden of proof” and
therefore a “substantive” rule that “governs in federal court”); Milam
v. State Farm Mut. Auto. Ins. Co., 972 F.2d 166, 170 (7th Cir. 1992)
(“[W]here a state in furtherance of its substantive policy makes it more
difficult to prove a particular type of state-law claim, the rule by which
it does this, even if denominated a rule of evidence or cast in
evidentiary terms, will be given effect in a diversity suit as an
expression of state substantive policy.”); Hemingway v. Ochsner
Clinic, 722 F.2d 1220, 1225 n.10 (5th Cir. 1984) (“[W]e find that the
[rule requiring expert testimony to prove the standard of care] is so
closely interrelated with the substantive cause of action of malpractice
in Louisiana that federal courts sitting in diversity cases should apply
the state rule in order to fully realize state substantive policy.”). See
also 29 CHARLES ALAN WRIGHT & VICTOR JAMES GOLD, FEDERAL
PRACTICE & PROCEDURE: EVIDENCE § 6263, at 204 (1997) (“[S]tate
law controls where it makes a precondition to recovery in a
medical-malpractice action the proffer of expert testimony to prove an
                                   12

tort cases involving areas of scientific or professional expertise
in which plaintiffs will be unable to find (honest, qualified)
experts who will testify that the defendants violated the relevant
scientific or professional standards. If brought in D.C. Superior
Court, such a case would be dismissed without ever getting to
the jury. If we were to refuse to enforce the D.C. expert
testimony requirement, however, the same case would reach the
jury if brought in federal district court. Such a result would be
outcome-determinative in the relevant sense. It would be likely
to “cause [the] plaintiff to choose the federal court.” Hanna,
380 U.S. at 468 n.9. And it would constitute “an ‘inequitable
administration’ of the law” because an action based on D.C. law,
which would be dismissed in D.C. Superior Court, would
“proceed through litigation to judgment in federal court solely
because of the fortuity that there is diversity of citizenship
between the litigants.” Walker, 446 U.S. at 753 (quoting Hanna,
380 U.S. at 468). Accordingly, we must enforce the D.C. rule
and affirm the judgment of the district court.9




element of the substantive-law claim, such as standard of care or
causation.” (footnotes omitted)).
     9
      As a last ditch effort, Burke urges us to reverse the district court
because it denied his request, made in his opposition to summary
judgment, that the court reopen discovery to allow him “to try to find
and designate such an expert” if the court “believes that the jury must
receive expert evidence as to the standard of care.” Pl.’s Mem. in
Opp’n to Def.’s Mot. for Summ. J. at 19. We review such denials for
abuse of discretion, see Messina v. Krakower, 439 F.3d 755, 762 (D.C.
Cir. 2006), and find no abuse here. As the district court noted, “Burke
filed his case in this forum; he should have considered -- at least
before the summary judgment phase -- that its law might be applied to
his claims such that an expert was needed.” 775 F. Supp. 2d at 21
n.12.
                            13

                            IV

   For the foregoing reasons, the district court’s grant of
summary judgment in favor of the defendants is

                                                  Affirmed.
