Amicus Curiae Brief — Hamed Kian, Petitioner v. Florida

No. 25-6623

In the Supreme Court of the United States

__________

HAMED KIAN,

Petitioner,

v.

STATE OF FLORIDA,

Respondent.

__________

On Writ of Certiorari to the

Fourth District Court of Appeal of Florida

__________

BRIEF OF THE CATO INSTITUTE AS AMICUS

CURIAE IN SUPPORT OF PETITIONER

__________

Harrison Prestwich

570 S. 300 W

Salt Lake City, UT 84101

harrisonprestwich

@gmail.com

Dated: August 13, 2026

Matthew P. Cavedon

Counsel of Record

Michael Z. Fox

CATO INSTITUTE

1000 Mass. Ave., N.W.

Washington, DC 20001

(706) 309-2859

mcavedon@cato.org

i

QUESTION PRESENTED

Whether Petitioner was deprived of his right,

under the Sixth and Fourteenth Amendments, to a

trial by a twelve-person jury.

ii

TABLE OF CONTENTS

Page(s)

QUESTION PRESENTED ........................................... i

TABLE OF CONTENTS.............................................. ii

TABLE OF AUTHORITIES ....................................... iv

INTEREST OF AMICUS CURIAE ............................. 1

SUMMARY OF ARGUMENT ..................................... 2

ARGUMENT ................................................................ 4

I. THE SIXTH AMENDMENT

INCORPORATES THE COMMON

LAW JURY WITH ALL OF ITS

UNENUMERATED ATTRIBUTES. ............... 4

A. The Constitutional Trial by Jury

Incorporates the Common Law

Jury’s Attributes. ...................................... 4

B. This Court Has Often Looked to

the Common Law to Identify the

Jury’s Unenumerated Attributes. ............ 8

II. THE COMMON LAW JURY

REQUIRES TWELVE JURORS. .................. 10

III.WILLIAMS’S FUNCTIONALIST

APPROACH HAS NO PLACE IN

SIXTH AMENDMENT

JURISPRUDENCE. ....................................... 12

A. Sixth Amendment “Functionalism”

Is Illegitimate. ......................................... 12

iii

B. Sixth Amendment “Functionalism”

Has Impaired the Jury’s Functions

in Civic Life. ............................................ 15

CONCLUSION .......................................................... 16

iv

TABLE OF AUTHORITIES

Page(s)

Cases

Am. Publ’g Co. v. Fisher, 166 U.S. 464 (1897) ............ 7

Apprendi v. New Jersey, 530 U.S. 466 (2000)

.................................................................... 6, 8, 9, 10

Ballew v. Georgia, 435 U.S. 223 (1978)................. 3, 15

Blakely v. Washington, 542 U.S. 296 (2004) ..... 6, 8, 10

Burch v. Louisiana, 441 U.S. 130 (1979) .............. 6, 13

Capital Traction Co. v. Hof, 174 U.S. 1 (1899) ......... 12

Cunningham v. Florida, 144 S. Ct. 1287

(2024) .................................................................. 2, 13

District of Columbia v. Heller, 554 U.S. 570

(2008) .............................................................. 4, 6, 13

Duncan v. Louisiana, 391 U.S. 145 (1968) ....... 3, 5, 12

Ex Parte Grossman, 267 U.S. 87 (1925) ...................... 5

Jones v. United States, 526 U.S. 227 (1999) ............... 6

Khorrami v. Arizona, 143 S. Ct. 22 (2022) ..... 5, 10, 12,

14, 15

Parklane Hosiery Co. v. Shore, 439 U.S. 322

(1979) ...................................................................... 15

Parsons v. Bedford, 28 U.S. 433 (1830)....................... 4

Patton v. United States, 281 U.S. 276 (1930)............ 12

Ramos v. Louisiana, 590 U.S. 83 (2020)

................................................................ 3, 7, 8, 9, 14

Rassmussen v. United States, 197 U.S. 516

(1905) ...................................................................... 12

v

Ring v. Arizona, 536 U.S. 584 (2002) .......................... 8

Thompson v. Utah, 170 U.S. 343 (1898) ........... 3, 5, 11

United States v. Gaudin, 515 U.S. 506 (1995) ...... 8, 10

Williams v. Florida, 399 U.S. 78 (1970)...... 2, 3, 13, 14

Other Authorities

Akhil Reed Amar, The Bill of Rights as a

Constitution, 100 YALE L.J. 1131 (1991)

.................................................................. 4, 5, 10, 16

Alexis de Tocqueville, Causes Mitigating

Tyranny in the United States, in

DEMOCRACY IN AMERICA (Henry Reeve ed.

1835) ....................................................................... 16

Hans Zeisel, And Then There Were None: The

Diminution of the Federal Jury, 38 U. CHI.

L. REV. 710 (1971) .................................................. 14

Jeffrey L. Fisher, Originalism as an Anchor

for the Sixth Amendment, 34 HARV. J.L. &

PUB. POL’Y 53 (2011) ................................................ 8

Joan L. Larsen, Ancient Juries and Modern

Judges: Originalism’s Uneasy Relationship

with the Jury, 71 OHIO ST. L.J. 959 (2010) ......... 4, 7

John Dickinson, Letters of Fabius IV (1788)............... 5

JOSEPH CHITTY, CHITTY’S CRIMINAL LAW

(1816) ...................................................................... 11

Kathleen M. O’Malley, Trial by Jury: Why It

Works and Why It Matters, 68 AM. U.L.

REV. 1095 (2019) ...................................................... 6

Larry T. Bates, Trial by Jury after Williams

v. Florida, 10 HAMLINE L. REV. 53 (1987).......... 7, 11

vi

Mary R. Rose et al., Selected to Serve: An

Analysis of Lifetime Jury Participation, 9 J.

EMPIRICAL LEGAL STUD. 33 (2012) ......................... 16

MATTHEW HALE, HISTORIA PLACITORUM

CORONÆ, THE HISTORY OF THE PLEAS OF THE

CROWN (1736) ......................................................... 11

Maxwell v. Dow, 176 U.S. 581 (1900).......................... 8

Michael J. Saks & Mollie Weighner Marti, A

Meta-Analysis of the Effects of Jury Size, 21

LAW & HUM. BEHAV. 451 (1997) ............................. 14

Note, The Changing Role of the Jury in the

Nineteenth Century, 74 YALE L.J. 170

(1964) .................................................................... 4, 5

Randy J. Holland, State Jury Trials and

Federalism: Constitutionalizing Common

Law Concepts, 38 VAL. U. L. REV. 373

(2004) ........................................................................ 7

Robert H. Miller, Comment, Six of One Is Not

a Dozen of the Other: A Reexamination of

Williams v. Florida and the Size of State

Criminal Juries, 146 U. PA. L. REV. 621

(1998) ...................................................... 7, 11, 12, 13

Shari S. Diamond et al., Achieving Diversity

on the Jury: Jury Size and the Peremptory

Challenge, 6 J. EMPIRICAL LEGAL STUD. 425

(2009) ...................................................................... 14

THE FEDERALIST No. 83 (Alexander Hamilton) .......... 2

Victoria A. Farrar-Myers & Jason B. Myers,

Echoes of the Founding: The Jury in Civil

Cases as Conferrer of Legitimacy, 54 S.M.U.

L. REV. 1857 (2001) ................................................ 15

vii

WILLIAM BLACKSTONE, COMMENTARIES (1769) ......... 11

WILLIAM SHAKESPEARE, KING LEAR ........................... 13

Constitutional Provisions

U.S. CONST. amend. V ................................................. 4

U.S. CONST. amend. VI ................................................ 2

U.S. CONST. amend. VII .............................................. 4

U.S. CONST. art. III, § 2, cl. 3 ...................................... 2

1

INTEREST OF AMICUS CURIAE1

The Cato Institute is a nonpartisan public policy

research foundation founded in 1977 and dedicated to

advancing the principles of individual liberty, free

markets, and limited government. Cato’s Project on

Criminal Justice was founded in 1999, and focuses on

the scope of substantive criminal liability, the proper

and effective role of police in their communities, the

protection of constitutional and statutory safeguards

for criminal suspects and defendants, citizen

participation in the criminal justice system, and

accountability for law enforcement.

Cato’s interest in this case arises from its

commitment to defending the jury’s constitutionally

assigned role as a vital check on government abuse, as

well from its interest in ensuring that criminal

defendants enjoy the full protection of the Sixth

Amendment.

1 Rule 37 statement: No part of this brief was authored by any

party’s counsel, and no person or entity other than amicus funded

its preparation or submission.

2

SUMMARY OF ARGUMENT

Hamed Kian was charged with five counts of

practicing chiropractic medicine with a suspended

license—a felony punishable by up to five years in

prison. Pet. Br. 14. Florida law authorizes criminal

defendants to be tried before six-person juries. Here, a

six-person jury convicted Mr. Kian on all counts. Id.

He appealed his conviction, arguing that the use of a

six-person jury violated his right to trial by jury under

the Sixth and Fourteenth Amendments. Id. The

appellate court affirmed his conviction without a

written opinion, and Mr. Kian subsequently asked this

Court to review his conviction. Id.

In trying criminal cases by six-person juries,

“Florida does what the Constitution forbids.”

Cunningham v. Florida, 144 S. Ct. 1287, 1287 (2024)

(Gorsuch, J., dissenting from denial of certiorari). The

common law criminal jury required twelve jurors. This

Court’s decision approving Florida’s deviation—

Williams v. Florida, 399 U.S. 78, 103 (1970)—broke

from centuries of tradition and should be overruled.

Trial by jury was exceptionally important to the

Framers. See THE FEDERALIST No. 83 (Alexander

Hamilton) (“The friends and adversaries of the plan of

the convention, if they agree in nothing else, concur at

least in the value they set upon the trial by jury”). In

the Constitution, they directed that the trial of federal

criminal cases “shall be by jury” and enumerated

defendants’ right to trial by jury because they

understood that, for centuries, citizen juries have

acted as a vital check on government overreach. U.S.

CONST. art. III, § 2, cl. 3; amend. VI. These provisions

drew little deliberation because the Framers readily

understood the importance—and contours—of the

3

venerable common law institution they sought to

protect.

While the Constitution’s text does not spell out

those contours in detail, this Court has rightly begun

looking to historical practices to recognize and enforce

aspects of the jury it incorporates. See Ramos v.

Louisiana, 590 U.S. 83, 90 (2020) (holding that the

Sixth Amendment requires a unanimous criminal jury

verdict). Protecting the common law jury bolsters the

legitimacy of courts and increases civic engagement.

One central requirement of the common law jury is

the need for twelve people to serve in criminal cases.

Twelve-person juries remained the undisputed norm

for centuries, required by this Court until Williams.

See, e.g., Thompson v. Utah, 170 U.S. 343, 346 (1898)

(someone charged with a felony “could not have been

tried by a jury of a less number than twelve”); Duncan

v. Louisiana, 391 U.S. 145, 152 (1968). Williams

unjustifiably went astray. This Court should overrule

it and restore the common law jury ensured by the

Constitution.

In doing so, this Court should make clear that

Williams’s “functionalist” approach has no place in

determining the scope of the constitutionally required

jury. Williams decided that certain attributes of the

common law jury are not incorporated into the

Constitution if they can be discarded without

impairing the jury’s “function.” Williams, 399 U.S. at

99. This holding quickly devolved into arbitrary and

untenable line-drawing. See Ballew v. Georgia, 435

U.S. 223 (1978). In overruling Williams, this Court

should confirm that the “very enumeration of the

right” at issue “takes out of the hands of government—

even the Third Branch of Government—the power to

4

decide on a case-by-case basis whether the right is

really worth insisting upon.” District of Columbia v.

Heller, 554 U.S. 570, 634 (2008). This Court should

reverse the decision below.

ARGUMENT

I.

THE SIXTH AMENDMENT INCORPORATES

THE COMMON LAW JURY WITH ALL OF

ITS UNENUMERATED ATTRIBUTES.

A. The Constitutional Trial by Jury

Incorporates the Common Law Jury’s

Attributes.

The Founding Generation understood that trial by

jury was integral to individual liberty. Trial by jury in

criminal cases was “the only right secured in all state

constitutions penned between 1776 and 1787.” Akhil

Reed Amar, The Bill of Rights as a Constitution, 100

YALE L.J. 1131, 1183 (1991). It is found in Article III

of the Constitution and the Sixth Amendment. Plainly,

“[t]he Constitution is obsessed with juries.” Joan L.

Larsen, Ancient Juries and Modern Judges:

Originalism’s Uneasy Relationship with the Jury, 71

OHIO ST. L.J. 959, 964 (2010); see also U.S. CONST.

amends. V, VII; Amar, supra, at 1190 (“If we seek a

paradigmatic image underlying the Bill of Rights, we

cannot go far wrong in picking the jury.”).

The jury’s pervasive presence in the Constitution

reflects the “prevailing political philosophy” of the

Founding Era: “popular control over, and participation

in, government should be maximized.” Note, The

Changing Role of the Jury in the Nineteenth Century,

74 YALE L.J. 170, 172 (1964). Americans have guarded

criminal trial by jury zealously since the Founding. See

Parsons v. Bedford, 28 U.S. 433, 446 (1830). The

5

Framers knew the jury served a critical, structural

role when they secured it in the Constitution. The

Sixth Amendment preserves this institution—and the

attributes it developed over centuries.

The jury’s primary function was to operate as a

check on government. See Amar, supra, at 1183 (“the

key role of the jury was to protect ordinary individuals

against governmental overreaching”). Its repeated

inclusion in the Constitution and Bill of Rights

“reflect[s] a profound judgment about the way in which

law should be enforced and justice administered.”

Duncan, 391 U.S. at 155. The accused are protected

“against the corrupt or overzealous prosecutor and

against the compliant, biased, or eccentric judge.” Id.

at 156. The Framers had “faith in the ability of the

common people” to adjudicate conduct in their own

communities rather than leaving that task to

government officials. Note, supra, at 172.

This confidence was founded on centuries of

experience with the petit criminal jury as it existed at

common law, an institution the Framers viewed as

their “birth right.” John Dickinson, Letters of Fabius

IV (1788).2 “From the moment it was adopted, the

Sixth Amendment was widely understood to protect”

the common law jury. Khorrami v. Arizona, 143 S. Ct.

22, 23 (2022) (Gorsuch, J., dissenting from denial of

certiorari). As this Court has explained, the institution

carried “the meaning affixed to [it] in the law as it was

in this country and in England at the time of the

adoption.” Thompson, 170 U.S. at 350; see also Ex

Parte Grossman, 267 U.S. 87, 108–09 (1925) (“The

language of the Constitution cannot be interpreted

2 Available at https://tinyurl.com/52mvzrrz.

6

safely except by reference to the common law and to

British institutions as they were when the instrument

was framed and adopted.”).

The Framers “were not prepared to leave [criminal

justice] to the State” and later political discretion,

“which is why the jury-trial guarantee was one of the

least controversial provisions of the Bill of Rights.”

Apprendi v. New Jersey, 530 U.S. 466, 498 (2000)

(Scalia, J., concurring); see also Blakely v. Washington,

542 U.S. 296, 308 (2004). They feared that trial by jury

“could be lost not only by gross denial, but by erosion.”

Jones v. United States, 526 U.S. 227, 248 (1999). They

constitutionally enshrined it as a “fundamental

reservation of power” that establishes popular control

over the judiciary. Blakely, 542 U.S. at 306. Like other

fundamental guarantees, it is not subject to “a

freestanding ‘interest-balancing’ approach.” Heller,

554 U.S. at 634. “Constitutional rights are enshrined

with the scope they were understood to have when the

people adopted them, whether or not future

legislatures or (yes) even future judges think that

scope too broad.” Id. at 634–35.

When courts fail to uphold the common law jury

trial required by the Constitution, “it is inevitable”

that arbitrary lines will be “drawn somewhere” as a

substitute. Burch v. Louisiana, 441 U.S. 130, 137

(1979). This judicial lawmaking tends to erode “the

rare opportunity for individuals . . . to participate in

our democracy.” Kathleen M. O’Malley, Trial by Jury:

Why It Works and Why It Matters, 68 AM. U. L. REV.

1095, 1109 (2019). Courts have previously weakened

trial by jury by “depart[ing] from [its] strictly

historical requirements.” Burch, 441 U.S. at 137. Once

that line is crossed, there are “no principled stopping

7

points for the Court to prevent further erosion.” Robert

H. Miller, Comment, Six of One Is Not a Dozen of the

Other: A Reexamination of Williams v. Florida and the

Size of State Criminal Juries, 146 U. PA. L. REV. 621,

628 (1998).

The Constitution is meant to prevent this. While its

text does not detail what a jury is or what trial by one

entails, the guarantee “surely meant something—

otherwise, there would have been no reason to write it

down.” Ramos, 590 U.S. at 89. It “carried with it some

meaning about the content and requirements of a jury

trial.” Id. And that content must have been “fixed” or

else it could “scarcely [be] a constitutional command.”

Larsen, supra, at 963; see also id. (“not everything

about jury trials can be up for grabs”); Am. Publ’g Co.

v. Fisher, 166 U.S. 464, 467 (1897) (the jury right

includes “not merely” its form, “but also all its

substantial elements”). “Any imprecision here seems

less to invite innovation than to assume that the words

of the text are themselves sufficiently precise to convey

a particular meaning.” Larsen, supra, at 991.

History clarifies that meaning. The jury is an

institution “long pre-dating the Constitution, even on

American soil,” which is why “[l]ittle additional

explanation was likely needed.” Id. at 991–92. “The

Framers’ reference to trial by jury in article III of the

Constitution, and again in the sixth amendment could

not have meant anything but a common-law jury.”

Larry T. Bates, Trial by Jury after Williams v. Florida,

10 HAMLINE L. REV. 53, 68 (1987); see also Randy J.

Holland, State Jury Trials and Federalism:

Constitutionalizing Common Law Concepts, 38 VAL. U.

L. REV. 373, 383 (2004) (the Framers viewed Article III

as “perpetuat[ing] the right to trial by jury in criminal

8

matters as it had existed at common law”). The

Framers “were seeking to ensure that their children’s

children would enjoy the same hard-won liberty they

enjoyed,” Ramos, 590 U.S. at 100—trial by jury as

defined by its common law attributes.

B. This Court Has Often Looked to the

Common Law to Identify the Jury’s

Unenumerated Attributes.

Accordingly—Williams being a conspicuous

exception—this Court has looked to the common law

to give the constitutionally guaranteed trial by jury

“intelligible content.” Blakely, 542 U.S. at 305;

Apprendi, 530 U.S. at 499 (Scalia, J., concurring).

Historical practices have shaped its understanding of

the meaning and scope of the jury trial right. See e.g.,

Maxwell v. Dow, 176 U.S. 581 (1900); United States v.

Gaudin, 515 U.S. 506, 515 (1995) (“We do not doubt

that historical practice is relevant to what the

Constitution means by such concepts as trial by jury”).

“The historical foundation” of the jury as it descended

“down centuries into the common law” has guided

much of the Court’s precedent. Apprendi, 530 U.S. at

477 (majority opinion); see also Ring v. Arizona, 536

U.S. 584, 599 (2002); Blakely, 542 U.S. at 308

(recognizing that “the Framers put a jury-trial

guarantee in the Constitution” to foreclose judicial

redefinition). For decades, the Court has followed “an

originalist interpretation.” Jeffrey L. Fisher,

Originalism as an Anchor for the Sixth Amendment, 34

HARV. J.L. & PUB. POL’Y 53, 56 (2011); see also Ramos,

590 U.S. at 89–90.

The Court has thus recognized jury attributes the

text never mentions but that are part of the common

law institution. The Court’s most thoroughly

9

originalist analysis was in Ramos v. Louisiana, where

the petitioner challenged the permissibility of

nonunanimous criminal jury verdicts. 590 U.S. at 87.

The Court recognized that the Sixth Amendment “says

nothing else about what a ‘trial by an impartial jury’

entails,” but refused to treat the constitutional

guarantee as “hollow.” Id.

So the Court looked to the common law. It

examined Blackstone, early state constitutions, and

legal treatises, finding that “unanimous verdicts had

been required for about 400 years” before the

Constitution’s ratification. Id. at 90–91. The Court

rejected a state contention that the absence of the word

“unanimity” in the constitutional provisions changed

“the meaning of the text that remains.” Id. at 98. If

that were true, then all the jury’s “accustomed

requisites”—“everything history might have taught us

about what it means to have a jury trial”—would have

to be discarded. Id. But it “can’t be right” that the

Constitution would impose a requirement “devoid of

meaning.” Id. The Court thus concluded that

unanimity was one of the “accustomed requisites” of

the common law jury enacted into the Constitution. Id.

at 97.

The Court used the same methodology in Apprendi

v. New Jersey and its progeny. In Apprendi, the Court

determined the constitutionality of sentence

enhancements based on fact findings made by the

judge, rather than the jury. Apprendi, 530 U.S. at 468–

69. While there is no constitutional text requiring the

jury to find sentence-aggravating facts, this

requirement existed in “longstanding tenets of

common-law criminal jurisprudence” acknowledged by

“courts and treatises since the earliest days of

10

graduated sentencing,” so it is constitutionally

required. Blakely, 542 U.S. at 301–02.

Relatedly and “equally well founded” at the

common law was the “companion right” to have guilt

proven beyond a reasonable doubt before conviction.

Apprendi, 530 U.S. at 478. While the Constitution is

silent as to the burden of proof, the “demand for a

higher degree of persuasion in criminal cases was

recurrently expressed from ancient times” and

recognized at the Founding—meaning it, too, is part of

the meaning of constitutional trial by jury. Id.; see also

Gaudin, 515 U.S. at 510 (describing this rule as having

“an impressive pedigree”).

The Sixth Amendment says nothing about

sentencing enhancements, the unanimity of verdicts—

or the required number of jurors. Yet, apart from

Williams, this Court has recognized historical

attributes as incorporated into the constitutional text.

It has worked to restore the jury that had devolved into

“a shadow of its former self.” Amar, supra, at 1190.

This case presents the opportunity to continue that

work by restoring the common law numerosity

requirement, and to further confirm the importance of

originalism.

II. THE COMMON LAW JURY REQUIRES

TWELVE JURORS.

The common law jury required twelve jurors.

Khorrami, 143 S. Ct. at 23 (Gorsuch, J., dissenting

from denial of certiorari) (“By the time of the Sixth

Amendment’s adoption, the 12-person criminal jury

was ‘an institution with a nearly four-hundred-yearold tradition in England.’”) (quoting Miller, supra, at

11

643). Williams erred in misconstruing the Sixth

Amendment to guarantee less.

The precise historical origin of twelve-person juries

is disputed. “Scholars have traced the origins to

sources as diverse as ancient Greece, the Roman

Conquest, [and] the Biblical importance of the number

twelve . . . .” Miller, supra, at 632. The “general

infrastructure of the criminal jury as a twelve-member

body rendering unanimous verdicts was clearly

established by the time of Edward III in 1377.” Id. at

638–39. Pre-colonial English legal authorities

reflected this. 4 WILLIAM BLACKSTONE, COMMENTARIES

*343 (1769) (general verdicts should be rendered “by

the unanimous suffrage of twelve of his equals and

neighbors”); 2 MATTHEW HALE, HISTORIA PLACITORUM

CORONÆ, THE HISTORY OF THE PLEAS OF THE CROWN

161 (1736) (“But in case of a trial by petit jury, it can

be by no more or less than twelve, and all affirming to

the verdict”); 2 JOSEPH CHITTY, CHITTY’S CRIMINAL

LAW 505 (1816) (“The petit jury, when sworn, must

consist precisely of twelve, and is never to be either

more or less”).

The common law jury was “brought over and

immediately integrated, unchanged, into preRevolutionary War America.” Miller, supra, at 643. It

“seems clear that to most of the delegates to the

Constitutional Convention in 1787, trial by jury in

criminal cases meant trial by a body of twelve persons

all of whom agreed to the verdict.” Bates, supra, at 66.

This was apparently so “obvious” as to receive no

debate at the convention itself. See id.

That view was unchallenged for most of American

history. See, e.g., Thompson, 170 U.S. at 351 (a

“unanimous verdict of a jury of twelve persons” was

12

the defendant’s “constitutional right”); Capital

Traction Co. v. Hof, 174 U.S. 1, 13 (1899) (trial by jury

in the “American constitutions” is “a trial by a jury of

twelve men”); Rassmussen v. United States, 197 U.S.

516, 529 (1905) (trial by jury means “a trial by the

historical, common law jury of twelve persons”); Patton

v. United States, 281 U.S. 276, 290 (1930) (the

“common law elements” of a twelve-person jury are

“embedded in the constitutional provisions”). By the

early 20th century, the Court had held that the

numerosity requirement was “not open to question.”

Khorrami, 143 S. Ct. at 25 (Gorsuch, J., dissenting

from denial of certiorari) (quoting Patton, 281 U.S. at

288).

“Decided against this backdrop, Williams was an

anomaly the day it was issued in 1970.” Id. at 24.

Indeed, just two years before, the Court had reaffirmed

the twelve-person requirement. See Duncan, 391 U.S.

at 151–52. In deciding that this was not in fact a

“necessary ingredient,” Williams had to reject “eight

hundred years of settled jurisprudence.” Miller, supra,

at 621.

The Court should overrule Williams as a deviation

from the original meaning of trial by jury.

III. WILLIAMS’S FUNCTIONALIST APPROACH

HAS NO PLACE IN SIXTH AMENDMENT

JURISPRUDENCE.

A. Sixth Amendment “Functionalism” Is

Illegitimate.

Like King Lear’s daughters, the Court soon found

that a number made negotiable is subject to endless

negotiation: “Goneril: Hear me, my lord. What need

you five-and-twenty, ten or five? Regan: What need

13

one?” WILLIAM SHAKESPEARE, KING LEAR act 2, sc. 4, ll.

300–03. Just a few years after Williams permitted

states to try criminal defendants before six-person

juries, the Court found itself having to explain why the

number of jurors could not fall further. The Court

reasoned that judicial line-drawing was inevitable—

admitting that its choice to set them at six is not

“wholly satisfactory.” Burch, 441 U.S. at 137–38.

Instead of history, the Williams Court chose to rely

on “functionalism,” substituting “bad social science for

careful attention to the Constitution’s original

meaning.” Cunningham, 144 S. Ct. at 1288 (Gorsuch,

J., dissenting from denial of certiorari); see also Heller,

554 U.S. at 634–35 (rejecting ahistorical “interestbalancing” approaches to the Bill of Rights). Williams

concluded that the number twelve was “a historical

accident” resting on “little more than mystical or

superstitious insights.” Williams, 399 U.S. at 88–89

(referring to “12 apostles, 12 stones, 12 tribes, etc.”). It

held that courts should instead ask whether a lesser

number of jurors could perform the same “function.”

Id. at 99.

Despite claiming empirical grounding for equating

six jurors to twelve, the Court’s evidence “spanned

only three paragraphs of the twenty-six-page majority

opinion.” Miller, supra, at 652. The Court cited “six

social-science ‘experiments’” that have since been

rebutted as “entirely unreliable, and in fact . . . not

‘experiments’ at all”—much less ones answering the

constitutional question for which the Court

repurposed them. Id. at 652–54; see also Williams, 399

U.S. at 101 (acknowledging having considered only a

“few experiments”). “This is scant evidence by any

standards.” Hans Zeisel, And Then There Were None:

14

The Diminution of the Federal Jury, 38 U. CHI. L. REV.

710, 715 (1971).

Unsurprisingly, the Court’s functionalist claims

“have not aged well.” Khorrami, 143 S. Ct. at 26

(Gorsuch, J., dissenting from denial of certiorari). The

Williams Court claimed that a six-member jury could

“prevent oppression by the Government” because it

was “large enough to promote group deliberation” and

represent a cross-section of the community. Williams,

399 U.S. at 100. Research has contradicted both

claims. A systematic review found: “Trial testimony

was discussed more accurately in the deliberations of

larger juries.” Michael J. Saks & Mollie Weighner

Marti, A Meta-Analysis of the Effects of Jury Size, 21

LAW & HUM. BEHAV. 451, 459 (1997). Larger juries

were better at remembering the evidence. Id. They

were more likely to reach a deadlock, and they paid

greater attention to minority voices. Id. at 459, 461.

Further, twelve-person juries are significantly

more likely to have minority members. Shari S.

Diamond et al., Achieving Diversity on the Jury: Jury

Size and the Peremptory Challenge, 6 J. EMPIRICAL

LEGAL STUD. 425, 449 (2009). Their voices aid

defendants by “improv[ing] the quality of

deliberation,” and their inclusion “increases de facto

legitimacy” because the “perceived fairness of the jury

system depends” on its ability to reflect the

community. Id. at 425–26.

Though the Williams Court mishandled social

science, its greater error was relying on it in the first

place. Ramos, 590 U.S. at 100 (holding that the jury

guarantee should never have been subjected to a

“functionalist assessment”). The Court soon changed

course yet again. Just a few years later, when asked to

15

allow for five-member juries, the Court admitted: “we

do not pretend to discern a clear line between six

members and five.” Ballew, 435 U.S. at 239. Judicial

whims were all that remained.

“None of this supplies a sound basis for judicial

tinkering with an ancient tradition,” Khorrami, 143 S.

Ct. at 26 (Gorsuch, J., dissenting from denial of

certiorari). The Framers constitutionally enshrined

trial by jury, fearing it would otherwise degrade over

time. Their foresight long protected it, until Williams.

This Court should reject that decision’s arbitrary

functionalism and restore originalism as the way to

make sense of trial by jury.

B. Sixth Amendment “Functionalism” Has

Impaired the Jury’s Functions in Civic

Life.

Ironically, Williams’s functionalism has harmed

more than just the coherence of the law—it has

undermined the jury’s function in American life by

threatening to reduce the number of people who decide

criminal cases. Jury service connects citizens to

government and builds confidence in the justice

system. The jury has always “provided a means by

which the American citizenry could participate in and

make decisions regarding the political system.”

Victoria A. Farrar-Myers & Jason B. Myers, Echoes of

the Founding: The Jury in Civil Cases as Conferrer of

Legitimacy, 54 S.M.U. L. REV. 1857, 1858 (2001). As

the jury is the most “direct expression of popular

sovereignty,” its members can make known

Americans’ “communal values.” Id. at 1868; see

Parklane Hosiery Co. v. Shore, 439 U.S. 322, 355

(1979) (Rehnquist, J., dissenting) (a group of ordinary

citizens brings “common sense and community values”

16

and avoids the “stereotypes said to infect the judicial

eye”).

Alexis de Tocqueville thought that jury service was

“the soundest preparation for free institutions”

because it “imbues all classes” with respect for public

liberty under law. Alexis de Tocqueville, Causes

Mitigating Tyranny in the United States, in

DEMOCRACY IN AMERICA (Henry Reeve ed. 1835).3

Modern empirical research confirms that citizens who

sit on a criminal jury “are more likely to vote in an

election.” Mary R. Rose et al., Selected to Serve: An

Analysis of Lifetime Jury Participation, 9 J. EMPIRICAL

LEGAL STUD. 33, 34 (2012). They also “tend to come

away with more favorable impressions of the legal

system.” Id. The jury room is where Americans “learn

self-government by doing self-government.” Amar,

supra, at 1187.

The jury is part of Americans’ self-governance.

Restoring the numerosity requirement and so

increasing the size of juries would advance this

important function intended by the Framers.

CONCLUSION

Each attribute of common law trial by jury—a

unanimous verdict, proof beyond a reasonable doubt,

juror factfinding, jury numerosity—is included in the

Constitution’s guarantees. Williams erred by thinking

its law-chamber social science knew better than the

wisdom of the centuries relied upon by the Framers. It

did not. That case should be overruled and the decision

below reversed.

3 Available at https://tinyurl.com/czu2ujyv.

17

Respectfully submitted,

Matthew P. Cavedon

Harrison Prestwich

Counsel of Record

570 S. 300 W

Michael Z. Fox

Salt Lake City, UT 84101 CATO INSTITUTE

harrisonprestwich

1000 Mass. Ave., N.W.

@gmail.com

Washington, DC 20001

(706) 309-2859

mcavedon@cato.org

Dated: August 13, 2026