Brooks v. Mitsubishi Electric & Electronics US, Inc.

District of Columbia Court of Appeals·Decided July 16, 2026·No. 24-CV-0739·Published

Opinion

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DISTRICT OF COLUMBIA COURT OF APPEALS

No. 24-CV-0739

JEAN R. BROOKS, et al., APPELLANTS,

V.

MITSUBISHI ELECTRIC AND ELECTRONICS USA, INC., et al., APPELLEES.

Appeal from the Superior Court of the District of Columbia (2012-CA-003241-B)

(Alfred S. Irving, Jr., Judge)

(Argued April 14, 2026 Decided July 16, 2026)

Jesenka Mrdjenovic argued for appellants.

Terrence J. Dee argued for appellees.

Many additional counsel were on the briefs for the parties. Their names are listed in an appendix to this opinion.

Before EASTERLY and SHANKER, Associate Judges, and THOMPSON, Senior Judge.

Opinion for the court by Associate Judge Easterly.

Dissenting opinion by Senior Judge THOMPSON at page 49.

EASTERLY, Associate Judge: For a quarter of a century, the same collection of

plaintiffs’ lawyers has been trying to hold the same collection of defendant cellphone 2

companies liable for injuries that an ever-expanding group of complainants allegedly

suffered as a result of cellphone radiation exposure. This court has already decided

three appeals in these cases. In Murray v. Motorola, Inc., 982 A.2d 764, 768, 778-89

(D.C. 2009) (Motorola I), we held that six complaints filed in 2001 and 2002 by

plaintiffs who were either individuals suffering from brain tumors or estates suing

on behalf of decedents who had died from brain tumors were not wholly preempted

by federal law. Litigation of these cases—at some point consolidated with another

eight complaints to become the Murray cases—proceeded until the defendants

appealed from an adverse-in-part Frye/Dyas ruling. In Motorola v. Murray, 147 A.3d

751, 752, 756-57, 759 (D.C. 2016) (en banc) (Motorola II), we retired the standard

for the admission of expert testimony under Frye v. United States, 293 F. 1013 (D.C.

Cir. 1923), and Dyas v. United States, 376 A.2d 827 (D.C. 1977), and adopted the

standard set forth in Daubert v. Merrell Dow Pharms., Inc., 509 U.S. 579 (1993),

and Federal Rule of Evidence 702; we then remanded for the Murray plaintiffs to

litigate the admissibility of their proffered expert testimony under Daubert/Rule 702.

In Murray v. Motorola, 339 A.3d 152, 156, 174 (D.C. 2025) (Motorola III), we

upheld the trial court’s ruling excluding the Murray plaintiffs’ proffered expert

testimony under Daubert/Rule 702. In so doing we affirmed the court’s decisions

denying the Murray plaintiffs’ motions for additional discovery and new experts and

striking portions of their expert reports. Id. at 169-74. 3

Now, in this fourth related appeal, we consider whether the trial court correctly

determined that the Brooks plaintiffs—another group of complainants who shared

the same counsel as the Murray plaintiffs and whose eighteen later-filed complaints

were eventually separately consolidated—were bound by litigation regarding

whether the Murray plaintiffs’ experts could testify about “general causation,” i.e.,

the causal connection between radiation from cellphones and the type of adverse

health effects at issue in the Murray (and Brooks) cases. We conclude that the Brooks

plaintiffs agreed—either expressly or implicitly—to be bound by both the

substantive outcome of the Murray litigation and all predicate procedural rulings,

and we discern no basis to declare those agreements nonbinding. Because the

testimony of the Murray plaintiffs’ experts was deemed inadmissible, we affirm the

trial court’s decision to grant the defendant cellphone companies summary judgment

on the ground that the Brooks plaintiffs lacked the requisite expert testimony to prove

their case.

I. Procedural History

A. The Initial Case Management Order in the Murray Cases

We begin our recap of the procedural history with the bifurcation of the

litigation in the Murray cases in the trial court’s initial case management order and

the contemporaneous litigation about the order’s meaning. 4

On November 15, 2011, the presiding judge, Judge A. Franklin Burgess, Jr.,

held a case management hearing in the Murray cases. At the hearing, the plaintiffs

suggested an alternative to “full discovery . . . [in] 14 cases” on overlapping issues

and proposed that the trial court focus first on determining whether plaintiffs had

admissible expert testimony regarding the “general causation” question that

pertained to all of the plaintiffs—i.e., whether their experts could permissibly testify

that cellphone radiation causes the type of adverse health effects the plaintiffs had

experienced. The plaintiffs asserted that their suggested approach would be

“efficient” because the expert testimony issue could be dispositive: if the court

determined their “experts’ testimony [wa]s founded in science” and could be

presented to a jury, their cases could move forward, but “[i]f the court says no, [the

proffered expert] testimony is no good and strikes the witnesses, then most of this is

over with.” But even as the plaintiffs proposed to forgo “full blown discovery,” at

least at the outset of the case, as part of this plan, they indicated that they still wanted

to get discovery seemingly unrelated to a Frye/Dyas hearing on the admissibility of

their experts’ testimony about general causation, noting, for example, their desire to

obtain from defendants “internal correspondence between regulatory bodies and

manufacturers, between manufacturers and the trade associations.” For their part,

the defendants did not oppose bifurcating the case; but highlighting that no plaintiff

in these types of suits had ever “gotten an expert to a jury,” they countered that 5

plaintiffs should be required to first demonstrate that they had admissible expert

testimony as to both general causation and specific causation as to all the

complainants diagnosed with brain cancer.

Putting forward his own bifurcation plan, Judge Burgess decided that the

Murray plaintiffs would first address expert admissibility as to general causation

with only limited discovery to that end. Under this plan, the parties would have:

a Frye hearing directed toward and discovery direct[ed] toward whether there is some consensus among the scientific community that cellphone radiation can cause one of these four tumors or health effects as [plaintiffs] have defined it and that in order to do that, [plaintiffs] can have discovery directed toward that issue . . . but that will be the limit of the discovery at this point other than, of course, the deposition of the experts, all along toward trying to figure out whether [plaintiffs] can meet the Frye standard.

And Judge Burgess pushed back when plaintiffs’ counsel tried to expand the

boundaries of its ruling, stressing that “the issue [would] . . . be whether [plaintiffs’

experts’] methodology [is] satisfactory under Frye,” and thus that the defendants

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