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 AMERICAN CIVIL LIBERTIES

UNION, AMERICAN CIVIL LIBERTIES UNION

OF FLORIDA, THE RUTHERFORD

INSTITUTE, AND THE MACARTHUR JUSTICE

CENTER, AS AMICI CURIAE IN SUPPORT OF

PETITIONER

_______________________

CECILLIA D. WANG

DEVI M. RAO

AMERICAN CIVIL LIBERTIES

Counsel of Record

RODERICK & SOLANGE

UNION FOUNDATION

425 California Street,

MACARTHUR JUSTICE

CENTER

Suite 700

501 H Street NE, Suite 275

San Francisco, CA 94104

Washington, DC 20002

(202) 869-3434

devi.rao@macarthurjustice.org

Additional counsel listed on inside cover

BRANDON BUSKEY

PRIYANKA MENON*

AMERICAN CIVIL LIBERTIES

UNION FOUNDATION

125 Broad Street, 18th Floor

New York, NY 10004

JOHN W. WHITEHEAD

WILLIAM E. WINTERS

THE RUTHERFORD

INSTITUTE

109 Deerwood Road

Charlottesville, VA 22911

DANIEL TILLEY

AMERICAN CIVIL LIBERTIES

UNION FOUNDATION

OF FLORIDA

4343 W. Flagler Street

Suite 400

Miami, FL 33134

STUART BANNER

UCLA SCHOOL OF LAW

SUPREME COURT CLINIC

405 Hilgard Ave.

Los Angeles, CA 90095

*Admitted only in Maryland

Counsel for Amici Curiae

TABLE OF CONTENTS

TABLE OF AUTHORITIES ....................................... ii

INTEREST OF AMICI CURIAE ................................ 1

INTRODUCTION AND SUMMARY OF

ARGUMENT ............................................................... 2

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

A. Under English Common Law, a “Jury” Had

Twelve Members. .............................................. 5

B. When the Constitution was Ratified,

Americans Likewise Understood the Term

“Jury” To Mean a Group of

Twelve. ........ 8

C. Post-Ratification

Cases

and

Treatises

Demonstrate the Term “Jury” Was Originally

Understood To Carry Its Common-Law

Meaning—a Body of Twelve Members. ......... 11

D. Twelve-Member Juries Fulfilled the Historical

Purpose of the Jury

Right. ...................... 18

E. This Court’s Precedents Recognize the Original

Meaning of “Jury” Is a Body of Twelve. ......... 21

CONCLUSION .......................................................... 22

(i)

ii

TABLE OF AUTHORITIES

Cases

Page(s)

Apprendi v. New Jersey,

530 U.S. 466 (2000) .......................................... 4, 21

Arizona State Legislature v. Arizona

Indep. Redistricting Comm’n,

576 U.S. 787 (2015) ................................................ 7

Ballew v. Georgia,

435 U.S. 223 (1978) (plurality opinion) ......... 19, 20

Blakely v. Washington,

542 U.S. 296 (2004) .............................................. 18

Bowles v. State,

37 Tenn. 360 (1858) ............................................. 14

Briant v. Russel,

2 N.J.L. 146 (1806) ............................................... 15

Brown v. State,

8 Blackf. 561 (Ind. 1847) ...................................... 14

Burk v. State,

2 H. & J. 426 (Md. 1809) ...................................... 15

Byrd v. State,

2 Miss. 163 (1834) ................................................ 14

Cancemi v. People,

18 N.Y. 128 (1858)................................................ 15

Capital Traction Co. v. Hof,

174 U.S. 1 (1899) .................................................. 21

iii

Carpenter v. State,

5 Miss. 163 (1839) .......................................... 13, 20

Chiafalo v. Washington,

591 U.S. 578 (2020) ............................................... 4

Cowles v. Buckman,

6 Iowa 161 (1858) ................................................. 14

Cunningham v. Florida,

144 S. Ct. 1287 (2024) ........................................... 4

District of Columbia v. Heller,

554 U.S. 570 (2008) ................................................ 7

Dixon v. Richards,

3 Miss. 771 (1838) ................................................ 15

Doebler v. Commonwealth,

3 Serg. & Rawle 237 (Pa. 1817) ........................... 14

Edwards v. Vannoy,

593 U.S. 255 (2021) ............................................ 1, 4

Erlinger v. United States,

602 U.S. 821 (2024) .................... 3, 8, 10, 18, 19, 22

Flowers v. Mississippi,

588 U.S. 284 (2019) .............................................. 18

Foote v. Lawrence,

1 Stew. 483 (Ala. 1828) ........................................ 15

Free Speech Coal., Inc. v. Paxton,

145 S. Ct. 2291 (2025) ............................................ 4

Grayson v. Cummins,

Dallam 391 (Tex. 1841) ........................................ 15

iv

Haaland v. Brackeen,

599 U.S. 255 (2023) ............................................... 4

Hemphill v. New York,

595 U.S. 140 (2022) ................................................ 4

Holmes v. Walton

(N.J. 1780) ............................................................ 10

Jackson v. State,

6 Blackf. 461 (Ind. 1843) ...................................... 14

Kennedy v. Bremerton Sch. Dist.,

597 U.S. 507 (2022) ................................................ 4

Khorrami v. Arizona,

143 S. Ct. 22 (2022) ........................ 1, 4, 8, 9, 12, 19

In re Klein,

14 F. Cas. 719 (D. Mo.) ........................................ 15

Larillian v. Lane & Co.,

8 Ark. 372 (1848) .................................................. 13

Maxwell v. Dow,

176 U.S. 581 (1900) .............................................. 21

Minor v. Florida,

146 S. Ct. 1668 (2026) ............................................ 1

NLRB v. Noel Canning,

573 U.S. 513 (2014) ................................................ 7

Norval v. Rice,

2 Wis. 22 (1853) .................................................... 15

Opinion of Justices, 41 N.H. 550 (1860) ................... 14

v

Parker v. Gladden,

385 U.S. 363 (1966) (per curiam) ........................ 20

Pena-Rodriguez v. Colorado,

580 U.S. 206 (2017) .............................................. 20

Pettis v. Warren,

1 Kirby 426 (Conn. Super. Ct. 1788) ................... 20

Ramos v. Louisiana,

590 U.S. 83 (2020) .................. 1, 3, 4, 10, 18, 20, 22

Rassmussen v. United States,

197 U.S. 516 (1905) .............................................. 21

Respublica v. Oswald,

1 U.S. 319 (Pa. 1788) ............................................. 9

Southern Union Co. v. United States,

567 U.S. 343 (2012) ................................................ 4

State v. Burket,

9 S.C.L. 155

(S.C. Const. Ct. App. 1818) .................................. 15

State v. Mansfield,

41 Mo. 470 (1867) ................................................. 16

State v. Meyers,

68 Mo. 266 (1878) ................................................. 14

State v. Parkhurst,

9 N.J.L. 427 (1802) ............................................... 10

Thompson v. Utah,

170 U.S. 343 (1898) .......................................... 3, 21

vi

United States v. Gaudin,

515 U.S. 506 (1995) ................................................ 4

United States v. Rahimi,

602 U.S. 680 (2024) ............................................... 4

United States v. Sprague,

282 U.S. 716 (1931) ................................................ 7

Williams v. Florida,

399 U.S. 78 (1970) .................................................. 3

Wolfe v. Martin,

2 Miss. 30 (1834) .................................................. 15

Work v. State,

2 Ohio St. 296 (1853) ............................... 13, 14, 20

Constitutional Provisions

U.S. Const. art. III, §2, cl. 3 ...................................... 10

N.J. Const. of 1776, art. XXII ..................................... 9

Other Authorities

John H. Baker, An Introduction to

English Legal History (4th ed. 2002) .................... 5

William Barton, Observations on the

Trial by Jury (Strasburg, Pa., 1803) ................... 12

Joseph Bingham, A New Practical

Digest of the Law of Evidence

(London, 1797)........................................................ 6

vii

1 Joel Prentiss Bishop, Commentaries

on the Law of Criminal Procedure

(Boston, 1866)....................................................... 16

4 William Blackstone, Commentaries on

the Laws of England (Oxford, 1769)................ 8, 21

3 John Bouvier, Institutes of American

Law (Philadelphia, 1851)..................................... 17

British Liberties, or the Free-born

Subject’s Inheritance (London, 1766) .................... 7

2 Richard Burn, A New Law Dictionary

(London, 1792)........................................................ 6

Burn’s Abridgment, or the American

Justice (Dover, N.H., 2d ed. 1792) ......................... 8

1 Joseph Chitty, A Practical Treatise on the

Criminal Law (Philadelphia, 1819) .................... 16

1 Edward Coke, The First Part of the

Institutes of the Laws of England

(Dublin, 16th ed. 1809) ........................................ 20

Thomas M. Cooley, A Treatise on the

Constitutional Limitations Which Rest

Upon the Legislative Power of the States

of the American Union (Boston, 1868) ................ 17

2 Timothy Cunningham, A New and

Complete Law-Dictionary

(London, 1765)........................................................ 6

Michael Dalton, The Country Justice

(London, 1727)........................................................ 6

viii

Giles Duncombe, Trials per Pais: or the

Law of England Concerning Juries

(London, 5th ed. 1718) ....................................... 5, 6

Henry Flanders, An Exposition of the

Constitution of the United States

(Philadelphia, 1860) ............................................. 17

Felix Frankfurter, Some Reflections on

the Reading of Statutes,

47 COLUM. L. REV. 527 (1947) .............................. 12

Matthew Hale, Conductor Generalis: or,

the Office, Duty and Authority of

Justices of the Peace

(Woodbridge, N.J., 1764) ....................................... 8

2 Matthew Hale, Historia Placitorum

Coronae: The History of the Pleas of

the Crown (London, 1736) ..................................... 5

John Hawles, The Englishman’s Right

(London, 1771)........................................................ 7

Francis Hilliard, The Elements of Law

(Boston, 1835)....................................................... 16

Letters of Delegates to Congress, 17741789 (Paul H. Smith ed., 1976):

Vol. 1 ....................................................................... 9

Vol. 24 ..................................................................... 9

Antonin Scalia & Bryan A. Garner,

Reading Law: The Interpretation of

Legal Texts (2012) ............................................... 12

ix

Arthur J. Stansbury, Elementary

Catechism on the Constitution of the

United States (Boston, 1828) ............................... 16

2 Joseph Story, Commentaries on the

Constitution of the United States

(Thomas M. Cooley ed., Boston,

4th ed. 1873) ............................................... 2, 16, 18

Peter Oxenbridge Thacher, Observations on

Some of the Methods Known in the Law

of Massachusetts to Secure the Selection

and Appointment of an Impartial Jury

in Cases Civil and Criminal

(Boston, 1834)....................................................... 16

The Debates in the Several State

Conventions, on the Adoption of the

Federal Constitution (Jonathan Elliot

ed., Washington, 2d ed. 1836):

Vol. 2 ..................................................................... 11

Vol. 3 ..................................................................... 11

The Declaration of Independence

(U.S. 1776) ............................................................ 19

THE FEDERALIST NO. 10

(James Madison) .................................................. 19

1 Papers of John Adams (Robert J.

Taylor ed., 1977)............................................. 18, 19

2 Bird Wilson, The Works of the

Honourable James Wilson, L.L.D.

(Philadelphia, 1804) ............................................... 9

x

Seymour D. Thompson & Edwin G.

Merriam, A Treatise on the

Organization, Custody and Conduct of

Juries, Including Grand Juries

(St. Louis, 1882) ................................................... 17

Thomas Wood, An Institute of the Laws

of England (London, 3d ed. 1724) ......................... 6

INTEREST OF AMICI CURIAE 1

The American Civil Liberties Union (the “ACLU”)

is a nationwide, non-profit, non-partisan organization

with more than 1.3 million members, founded in 1920

and dedicated to the principles of liberty and equality

enshrined in the Constitution. In support of those

principles, the ACLU has appeared before this Court

as amicus curiae in numerous cases concerning the

Sixth Amendment right to a jury trial, including:

Minor v. Florida, 146 S. Ct. 1668 (2026) (denying

certiorari); Khorrami v. Arizona, 143 S. Ct. 22 (2022)

(denying certiorari); Edwards v. Vannoy, 593 U.S. 255

(2021); Ramos v. Louisiana, 590 U.S. 83 (2020). The

American Civil Liberties Union Foundation of Florida

is a non-profit, non-partisan membership organization devoted to protecting civil rights and civil

liberties for all Floridians. It is a state affiliate of the

ACLU.

The Rutherford Institute is a nonprofit civil liberties organization headquartered in Charlottesville,

Virginia. Founded in 1982 by its President, John W.

Whitehead, the Institute provides legal assistance at

no charge to individuals whose constitutional rights

have been threatened or violated and educates the

public about constitutional and human rights issues

affecting their freedoms. The Rutherford Institute

works tirelessly to resist tyranny and threats to

freedom by seeking to ensure that the government

abides by the rule of law and is held accountable when

1 No counsel for a party authored this brief in whole or in part.

Neither of the parties or their counsel, nor any other person or

entity other than amici, their members, or their counsel made a

monetary contribution intended to fund the preparation or

submission of this brief.

(1)

2

it infringes on the rights guaranteed by the

Constitution and laws of the United States.

The Roderick and Solange MacArthur Justice

Center (“MJC”) is a national not-for-profit civil rights

organization founded in 1985 by the family of

J. Roderick MacArthur to advocate for civil and

human rights, and for a fair and humane criminal

legal system. MJC attorneys have played a key role in

advocacy on criminal legal system issues including

criminal procedure issues generally and Sixth

Amendment rights specifically. In addition to direct

representation on behalf of its clients, MJC frequently

files amicus briefs related to these issues throughout

the federal circuits, in state appellate courts, and in

this Court.

INTRODUCTION AND SUMMARY OF

ARGUMENT

The Sixth Amendment to the Constitution

guarantees the right to trial by jury. That guarantee

carries with it the Founding-era understanding that

the jury—“the great bulwark of [our] civil and political

liberties,” 2 Joseph Story, Commentaries on the

Constitution of the United States § 1779, at 540

(Thomas M. Cooley ed., Boston, 4th ed. 1873) (“Story,

Commentaries”)—must have twelve members to

convict the criminally accused.

The historical record is clear that the Sixth

Amendment guarantees the right to be tried by a

twelve-person jury. Under English common law, the

jury was a body of twelve. A group that was smaller or

larger could not deliver a verdict. When the

Constitution and the Bill of Rights were ratified, the

American common-law rule was identical. And

numerous post-ratification cases and treatises

demonstrate that the word “jury” in the Constitution

3

and the Bill of Rights was originally understood to

bear its common-law meaning: It required twelve

members.

This Court’s precedents have echoed this historical

understanding. See, e.g., Erlinger v. United States,

602 U.S. 821, 831 (2024) (recognizing that a criminal

defendant must be convicted “by the unanimous

suffrage of twelve of his equals and neighbours”)

(emphasis added; cleaned up); Ramos v. Louisiana,

590 U.S. 83, 92 (2020) (“[A] defendant enjoys a

‘constitutional right to demand that his liberty should

not be taken from him except by the joint action of the

court and the unanimous verdict of a jury of twelve

persons.’ ”) (quoting Thompson v. Utah, 170 U.S. 343,

351 (1898)) (emphasis added).

Yet, for half a century, criminal defendants in a

small minority of States have been subject to a

practice that never would have passed muster at our

nation’s Founding: being denied the right to a jury

comprised of twelve peers when their life and liberty

are in jeopardy. As described below, this Court’s

decision in Williams v. Florida, 399 U.S. 78 (1970), is

demonstrably inconsistent with the original meaning

of the Sixth Amendment. In Ramos, this Court

established that Williams’s mode of analysis is dead

wrong, and that the Sixth Amendment’s jury trial

clause is defined by its original public meaning. To the

extent that Ramos did not already overrule Williams,

this Court should do so now.

4

ARGUMENT

The Original Meaning of “Jury,” as the Term

Was Enshrined in the Constitution, Is a Body

with Twelve Members

The Sixth Amendment provides that, “[i]n all

criminal prosecutions,” the defendant has the right to

trial by “jury.” As this Court has explained, that

constitutional text must be “interpreted by reference

to historical practices and understandings.” Kennedy

v. Bremerton Sch. Dist., 597 U.S. 507, 535 (2022)

(cleaned up). 2 That is, the right to trial by “jury” in

criminal cases under the Sixth Amendment carries its

“original public meaning.” Ramos, 590 U.S. at 92;

accord Southern Union Co. v. United States, 567 U.S.

343, 353 (2012); Apprendi v. New Jersey, 530 U.S. 466,

477 (2000); United States v. Gaudin, 515 U.S. 506,

512-13, 516 (1995).

When the Bill of Rights was ratified, “jury” was a

familiar term under English and American common

law: It referred to a body of twelve members. See

Khorrami, 143 S. Ct. at 27 (Gorsuch, J., dissenting

from the denial of certiorari); accord Cunningham v.

Florida, 144 S. Ct. 1287, 1287 (2024) (Gorsuch, J.,

dissenting from the denial of certiorari). The Court

should therefore hold that the Sixth Amendment

2 Accord Free Speech Coal., Inc. v. Paxton, 145 S. Ct. 2291, 2303

(2025) (Thomas, J.); United States v. Rahimi, 602 U.S. 680, 691

(2024) (Roberts, C.J.); Haaland v. Brackeen, 599 U.S. 255, 28891 (2023) (Barrett, J.); Hemphill v. New York, 595 U.S. 140, 15052 (2022) (Sotomayor, J.); Edwards v. Vannoy, 593 U.S. 255, 266

(2021) (Kavanaugh, J.); Chiafalo v. Washington, 591 U.S. 578,

588 (2020) (Kagan, J.)

5

guarantees a constitutional right to a twelve-person

jury in criminal cases.

A.

Under English Common Law, a “Jury”

Had Twelve Members.

By the eighteenth century, the institution of the

twelve-member jury had been firmly established in

English law. “If a prisoner pleaded Not guilty, as most

did, and put himself on the country, twelve jurors

were sworn in.” John H. Baker, An Introduction to

English Legal History 509 (4th ed. 2002).

This requirement of twelve was emphasized in the

leading eighteenth-century treatise on English

criminal law, Matthew Hale’s History of the Pleas of

the Crown. At trial, Hale explained, “the jury are

commanded to look on the prisoners, and then

severally twelve of them, neither more nor less, are

sworn.” 2 Matthew Hale, Historia Placitorum

Coronae: The History of the Pleas of the Crown 293

(London, 1736). Hale observed that, if the jurors

numbered less than twelve, they had no power to act.

If one juror “goes out of town,” he noted, “whereby only

eleven remain, these eleven cannot give any verdict

without the twelfth.” Id. at 295. The eleven remaining

jurors had to “be discharged, and a new jury sworn,

and new evidence given, and the verdict taken of the

new jury.” Id. at 295-96. Likewise, “[i]f only eleven be

sworn by mistake, no verdict can be taken of the

eleven.” Id. at 296.

The same principle—that a jury must have twelve

members—was repeated in many other English

treatises of the period. The “Number must be Twelve,”

insisted one treatise on juries. Giles Duncombe, Trials

per Pais: or the Law of England Concerning Juries 79

(London, 5th ed. 1718). “And the Law is so precise in

6

this Number of Twelve, that if the Trial be by more or

less, it is a Mistrial.” Id. at 79-80. As another author

explained, “no One shall be Convict by Verdict, unless

the Offence is found . . . by Twelve (not more or less)

of the Petty Jury upon Trial.” Thomas Wood, An

Institute of the Laws of England 623 (London, 3d ed.

1724). Another treatise declared that “on a trial by a

petit jury no more nor less than twelve can be

allowed.” Joseph Bingham, A New Practical Digest of

the Law of Evidence 63 (London, 1797).

Manuals for judges explained that, when

conducting a criminal trial, exactly twelve jurors had

to be sworn. “[C]all the Foreman of the Jury, and say

to him, Lay your Hand on the Book,” instructed one

guidebook. Michael Dalton, The Country Justice 654

(London, 1727). Once the foreman had been sworn,

“[t]hen call the Second, and swear him in like Manner,

and so to Twelve; and neither more nor less must be

sworn.” Id. To be on the safe side, the judge was

advised to “count them Twelve” before proceeding any

further. Id.

Consistent with this historical understanding,

legal dictionaries of the era defined “jury” as a body of

twelve people. See 2 Timothy Cunningham, A New

and Complete Law-Dictionary (London, 1765)

(defining “jury” as body “of twelve, [which] can be

neither more nor less”) (unpaginated; quotation is

from section 3 of the definition of “jury”); 2 Richard

Burn, A New Law Dictionary 45 (London, 1792)

(“upon a trial by a petit jury, it can be by no more, nor

less, than 12”). These sources support the conclusion

that the ordinary meaning of “jury” is a twelvemember body, for constitutional interpretation is

“guided by the principle that ‘[t]he Constitution was

written to be understood by the voters; its words and

7

phrases were used in their normal and ordinary as

distinguished from technical meaning.’ ” District of

Columbia v. Heller, 554 U.S. 570, 576 (2008) (quoting

United States v. Sprague, 282 U.S. 716, 731 (1931))

(brackets in Heller); accord NLRB v. Noel Canning,

573 U.S. 513, 527 (2014) (using Founding-era

dictionary definition to ascertain original meaning);

Arizona State Legislature v. Arizona Indep.

Redistricting Comm’n, 576 U.S. 787, 813-14 (2015)

(similar).

The same point was made in works intended to

summarize the English legal system for a general

audience. “[B]y a fundamental law in our government,”

one book explained, no one could be convicted “for any

crime whatsoever, but upon being found guilty on two

several tryals (for so may that of the grand and petit

jury be called) and the judgment of twice twelve men

at least.” British Liberties, or the Free-born Subject’s

Inheritance 370 (London, 1766). The “twice twelve”

referred to the size of the grand and petit juries:

“twelve or more to find the bill of indictment against

him, and twelve others to give judgment upon the

general issue of Not guilty.” Id. The petit jury “always

consists of twelve men, and no more nor any less.” Id.

at 376-77 (footnote omitted). Another contemporary

author likewise observed that conviction of a crime

required the verdict of “no less than twelve honest,

substantial, impartial” jurors. John Hawles, The

Englishman’s Right 5 (London, 1771).

The requirement that juries have twelve members

was so well established in eighteenth-century England

that, when William Blackstone composed his

ubiquitous Commentaries, he did not need to belabor

the point, because it was already familiar to his

readers. Blackstone praised “[t]he antiquity and

8

excellence” of the English institution of jury trial,

which he contrasted with juryless places like “France

or Turkey,” where monarchs could “imprison,

dispatch, or exile any man that was obnoxious to the

government, by an instant declaration, that such is

their will and pleasure.” 4 William Blackstone,

Commentaries on the Laws of England 343 (Oxford,

1769) (“Blackstone, Commentaries”). It was one of “the

liberties of England” that one could not be convicted

of a crime without “the unanimous suffrage of twelve

of his equals and neighbours.” Id.; see Khorrami, 143

S. Ct. at 23 (Gorsuch, J., dissenting from the denial of

certiorari) (“[i]n 1769, Blackstone stated the rule

succinctly”); Erlinger, 602 U.S. at 831.

In the late eighteenth century, English law was

thus clear. A “jury” was a body with twelve members.

A group that was smaller could not render a verdict in

a criminal case.

B.

When the Constitution was Ratified,

Americans Likewise Understood the

Term “Jury” To Mean a Group of

Twelve.

American law in the Founding era largely

replicated English law. The size of criminal juries was

no exception. American guidebooks for judges, like

their English predecessors, instructed that juries

should be no smaller or larger than twelve. See

Matthew Hale, Conductor Generalis: or, the Office,

Duty and Authority of Justices of the Peace 393

(Woodbridge, N.J., 1764); Burn’s Abridgment, or the

American Justice 380 (Dover, N.H., 2d ed. 1792).

“In the 1790s, James Wilson, both a framer . . . and

a Justice . . . , explained the common-law rule”:

“[T]welve jurors is of indispensable necessity.”

9

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

from the denial of certiorari). In a series of lectures

delivered in 1790-1791, Wilson further defined a

“verdict” as “the joint declaration of twelve jurymen

upon their oaths.” 2 Bird Wilson, The Works of the

Honourable James Wilson, L.L.D. 343 (Philadelphia,

1804). And as Chief Justice McKean of the

Pennsylvania Supreme Court put it in 1788, “I have

always understood it to be the law, independent of

[the state constitution’s bill of rights], that the twelve

jurors must be unanimous in their verdict.”

Respublica v. Oswald, 1 U.S. 319, 323 (Pa. 1788)

(statement) (emphasis added).

The correspondence of members of the Continental

Congress likewise shows that juries were understood

to have twelve members. In one letter, John Dickinson

explained that the right to jury trial means “that

neither Life, Liberty, or property can be taken from

the Possessor, until twelve of his Countrymen and

Peers” reach a verdict. 1 Letters of Delegates to

Congress, 1774-1789, at 236, 238 (Paul H. Smith ed.,

1976). William Pierce of Virginia similarly insisted

that the criminal jury have twelve members: “The

solemnity of the trial by jury is suited to the nature of

criminal cases, because . . . the fact or truth of every

accusation . . . is to be confirmed by the unanimous

suffrage of twelve good men, ‘superior to all suspicion.’ ”

24 id. at 445, 448 (1996).

In fact, the requirement that juries have twelve

members was the basis for one of the first instances of

judicial review in the United States. New Jersey’s

constitution of 1776 provided that “the inestimable

Right of Trial by Jury shall remain confirmed.” N.J.

Const. of 1776, art. XXII. Although the state

constitution did not specify the size of the jury, the

10

New Jersey Supreme Court held in Holmes v. Walton

(N.J. 1780) that a statute providing for six-person

juries was void because a jury of six “was not a

constitutional jury.” State v. Parkhurst, 9 N.J.L. 427,

444 (1802). 3

The right to a jury trial in criminal cases is so

“fundamental to the American scheme of justice” that

it appears “not only in the Sixth Amendment, but also

in Article III.” Ramos, 590 U.S. at 89, 93; see U.S.

Const. art. III, § 2, cl. 3. So important was the jury at

the Founding that, “[i]n the ratification debates,”

“some questioned” whether the guarantee in Article

III alone sufficed. Erlinger, 602 U.S. at 830. “To

address this and other concerns about the new

Constitution, James Madison agreed to draft a series

of amendments we now know as the Bill of Rights,”

including the Sixth Amendment. Id.

During those disputes over whether the new

Constitution sufficiently protected the right to a jury

trial—a right that had to be “guarded with the most

jealous circumspection,” id. (cleaned up)—the delegates

understood that juries would have twelve members.

For instance, in the Virginia ratifying convention,

Edmund Randolph defended the Constitution against

the claim that it was deficient because it lacked a bill

of rights. 4 Randolph argued that no bill of rights was

necessary. “Is there not provision made, in this

Constitution, for the trial by jury in criminal cases?”

he asked. 3 The Debates in the Several State

3 Holmes was not reported, but it was discussed in Parkhurst.

4 Randolph was then the Commonwealth’s governor. When the

Constitution was ratified, he became the nation’s first attorney

general.

11

Conventions, on the Adoption of the Federal

Constitution 467 (Jonathan Elliot ed., Washington, 2d

ed. 1836). He insisted that there was no reason for the

Constitution to address the topic in any more detail,

because “[t]here is no suspicion that less than twelve

jurors will be thought sufficient.” Id.

On the other side of the Virginia debate, Patrick

Henry, the Commonwealth’s former governor,

attacked the Constitution for lacking a bill of rights.

He feared that “we are to part with that trial by jury

which our ancestors secured their lives and property

with.” Id. at 544. Henry extolled the jury as an

“excellent mode of trial,” because “[t]he unanimous

verdict of twelve impartial men cannot be reversed.”

Id.

In the Pennsylvania ratifying convention, Thomas

McKean, the Commonwealth’s chief justice, defended

the Constitution’s grant of appellate jurisdiction to

the Supreme Court by observing that, at common law,

appellate courts often reviewed the decisions of trial

courts, even in some cases tried to a jury. McKean

declared: “Juries are not infallible because they are

twelve in number.” 2 id. at 540.

C.

Post-Ratification Cases and Treatises

Demonstrate the Term “Jury” Was

Originally Understood To Carry Its

Common-Law Meaning—a Body of

Twelve Members.

The question sometimes arose in the early United

States: Was a body with less than twelve members a

“jury” as the term was used in the state and federal

constitutions? American courts and commentators

consistently held that it was not. They reasoned that

the word “jury” meant a jury with twelve members,

12

because the state and federal constitutions had

incorporated the conventional common-law understanding of the term. See Khorrami, 143 S. Ct. at 23

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

Trials thus required “a jury of twelve men, as now

established by the constitution.” William Barton,

Observations on the Trial by Jury 10 (Strasburg, Pa.,

1803).

Early American courts used the same interpretive

method that is still used today: When a legal text,

such as a constitution, includes a term with a wellestablished meaning, the term should be given that

meaning where no contrary intent appears. See

Antonin Scalia & Bryan A. Garner, Reading Law: The

Interpretation of Legal Texts 73 (2012). In the oftrepeated words of Justice Frankfurter, “if a word is

obviously transplanted from another legal source,

whether the common law or other legislation, it brings

the old soil with it.” Felix Frankfurter, Some

Reflections on the Reading of Statutes, 47 COLUM. L.

REV. 527, 537 (1947).

The word “jury,” as used in the state and federal

constitutions, thus meant the familiar twelve-member

body that had been standard for centuries. As one

court explained:

The trial by jury is a great constitutional

right, and when the convention incorporated

the provision into the constitution of the

country, they most unquestionably had

reference to the jury trial as known and

recognized by the common law. It is a well

ascertained fact, that the common law jury

consisted of twelve men, and as a necessary

consequence, since the constitution is silent

13

upon the subject, the conclusion is irresistable

[sic] that the framers of that instrument

intended to require the same number.

Larillian v. Lane & Co., 8 Ark. 372, 374-75 (1848).

The Mississippi Supreme Court agreed in

reversing a conviction by a jury of only eleven

members. Carpenter v. State, 5 Miss. 163 (1839). To

define the right to a trial by jury, the court observed,

“we must necessarily recur to the provisions of the

common law defining the qualifications, and

ascertaining the number of which the jury shall

consist; as the standard to which, doubtless, the

framers of our constitution referred.” Id. at 166.

Because “[a]t common law the number of the jury, for

the trial of all issues involving the personal rights and

liberties of the subject, could never be less than

twelve,” the same was necessarily true under the

constitution. Id.

The Ohio Supreme Court reached the same

conclusion. It began by noting that, in the

constitution, “the right of jury trial is recognized to

exist.” Work v. State, 2 Ohio St. 296, 302 (1853). The

court asked: “What, then, is this right? It is nowhere

defined or described in the constitution. It is spoken of

as something already sufficiently understood, and

referred to as a matter already familiar to the public

mind.” Id. The court reviewed the history of juries in

England and the United States, which showed

“beyond controversy the number of the jury at

common law . . . . The number must be twelve.” Id. at

304. Indeed, the court observed that the question of

fewer than twelve jurors “has seldom arisen, but

whenever it has, the same result has followed, without

a single dissenting opinion or dictum to the contrary.”

14

Id. at 306. The court accordingly reversed a conviction

obtained with a jury of less than twelve. Id. at 308.

Numerous other early state courts also reversed

convictions that flowed from a jury of less than twelve.

See Doebler v. Commonwealth, 3 Serg. & Rawle 237,

237 (Pa. 1817); Jackson v. State, 6 Blackf. 461, 461

(Ind. 1843); Brown v. State, 8 Blackf. 561, 561 (Ind.

1847); Bowles v. State, 37 Tenn. 360, 362-63 (1858);

State v. Meyers, 68 Mo. 266, 266 (1878); Byrd v. State,

2 Miss. 163, 177 (1834). Such a result was necessary

because a jury of less than twelve is “a fatal defect in

criminal cases, without hesitation.” Cowles v.

Buckman, 6 Iowa 161, 163 (1858).

The New Hampshire Supreme Court provided an

especially thorough discussion of the issue in response

to a request from the legislature for an opinion as to

whether the legislature had the authority to reduce

the size of juries. Opinion of Justices, 41 N.H. 550

(1860). “The terms ‘jury,’ and ‘trial by jury,’ are, and

for ages have been well known in the language of the

law,” the court began. Id. at 551. “They were used at

the adoption of the constitution, and always, it is

believed, before that time, and almost always since, in

a single sense. A jury for the trial of a cause was a

body of twelve men.” Id. When the constitution was

adopted, the court continued, “no such thing as a jury

of less than twelve men, or a jury deciding by less than

twelve voices, had ever been known, or ever been the

subject of discussion in any country of the common

law.” Id. at 552. For this reason, the court concluded

that “no body of less than twelve men, though they

should be by law denominated a jury, would be a jury

within the meaning of the constitution; nor would a

trial by such a body, though called a trial by jury, be

such, within the meaning of that instrument.” Id.

15

In short, early American courts consistently held

that juries must have twelve members. See Burk v.

State, 2 H. & J. 426, 426 (Md. 1809) (referring to “the

legal number of twelve sworn on the jury”); State v.

Burket, 9 S.C.L. 155, 155 (S.C. Const. Ct. App. 1818)

(“To constitute a jury, every lawyer knows that twelve

lawful men are necessary, and that without this

number no jury can exist[.]”); Foote v. Lawrence, 1

Stew. 483, 483 (Ala. 1828) (“The term jury is well

understood to be twelve men[.]”); Wolfe v. Martin, 2

Miss. 30, 31 (1834) (“There is no jury for the trial of

issues known to the constitution and laws of this

state, except that which consists of ‘twelve good and

lawful men[.]’ ”); Grayson v. Cummins, Dallam 391,

393 (Tex. 1841) (“It has been often ruled that a less

number than twelve is no jury[.]”); Dixon v. Richards,

3 Miss. 771, 771 (1838) (“The third error assigned is

fatal. A jury must consist of twelve men: no other

number is known to the law: here there was but

eleven. The judgment must be reversed.”); Norval v.

Rice, 2 Wis. 22, 26-29 (1853) (collecting sources

reflecting the common law and holding that the

constitutional right to trial by jury requires twelvemember juries); In re Klein, 14 F. Cas. 719, 729 (D.

Mo.) (No. 7,866) (“Could congress direct a trial by jury,

and provide that the jury should consist of three men;

and that a majority should convict? No person will

assert the affirmative.”), rev’d on other grounds, 42

U.S. (1 How.) 277 (C.C.D. Mo. 1843) (No. 7,865);

Cancemi v. People, 18 N.Y. 128, 135 (1858) (“A legal

jury, according to the common law, consists of twelve

persons; our constitution declares that ‘the trial by

jury, in all cases in which it has heretofore been used,

shall remain inviolate forever[.]’ ”) (citations omitted);

Briant v. Russel, 2 N.J.L. 146, 146 (1806) (“It

16

appeared by the record, that the cause was tried by

eleven jurors; for which cause the judgment was

reversed.”). As one court summarized, “[w]henever

there is a constitutional guaranty of the right of trial

by jury, the jury must be composed of twelve men.”

State v. Mansfield, 41 Mo. 470, 475 (1867).

Early American treatises reflected the consensus

that the Constitution’s use of the term “jury” required

a jury of twelve, because such was the accepted

meaning of the term at common law. See 2 Story,

Commentaries § 1779, at 541 (“[A] trial by jury is

generally understood to mean, ex vi termini [by

definition], a trial by a jury of twelve men, impartially

selected, who must unanimously concur in the guilt of

the accused before a legal conviction can be had. Any

law, therefore, dispensing with any of these

requisites, may be considered unconstitutional.”); 1

Joel Prentiss Bishop, Commentaries on the Law of

Criminal Procedure § 761, at 532 (Boston, 1866) (“[I]t

is a point upon which the authorities agree, that,

within the meaning of our constitutional provisions, a

jury of less than twelve men is not a jury; and a

statute authorizing a jury of less, in a case in which

the constitution guarantees a jury trial, is void.”); see

also Arthur J. Stansbury, Elementary Catechism on

the Constitution of the United States 63 (Boston, 1828)

(“[T]he jury consists of twelve persons[.]”); Peter

Oxenbridge Thacher, Observations on Some of the

Methods Known in the Law of Massachusetts to Secure

the Selection and Appointment of an Impartial Jury in

Cases Civil and Criminal 7 (Boston, 1834) (“The trial

by jury is by twelve free and lawful men[.]”); Francis

Hilliard, The Elements of Law 288 (Boston, 1835) (“A

jury consists of twelve men[.]”); 1 Joseph Chitty, A

Practical Treatise on the Criminal Law 411

17

(Philadelphia, 1819) (“The petit jury, when sworn,

must consist precisely of twelve . . . . If, therefore, the

number returned be less than twelve, any verdict

must be ineffectual, and the judgment will be

reversed[.]”); 3 John Bouvier, Institutes of American

Law § 3035, at 327 (Philadelphia, 1851) (“By jury is

understood a body of twelve[.]”); Henry Flanders, An

Exposition of the Constitution of the United States 217

(Philadelphia, 1860) (“A petit jury consists of twelve

men[.]”); Seymour D. Thompson & Edwin G. Merriam,

A Treatise on the Organization, Custody and Conduct

of Juries, Including Grand Juries § 6, at 6 (St. Louis,

1882) (“[W]here the record shows that the cause was

tried by a jury of less than twelve men, the trial will

be held to be a nullity[.]”).

In short, post-ratification interpretations support

the conclusion that the Framers incorporated the

original, common-law meaning of “jury” in the Sixth

Amendment—a twelve-member body. Michigan judge

Thomas Cooley summed up this consensus in his mid19th century treatise on constitutional law:

A petit, petty, or traverse jury is a body of

twelve men, who are sworn to try the facts of

a case as they are delivered from the evidence

placed before them. Any less than this

number of twelve would not be a common-law

jury, and not such a jury as the constitution

preserves to accused parties . . . .

Thomas M. Cooley, A Treatise on the Constitutional

Limitations Which Rest Upon the Legislative Power of

the States of the American Union 319 (Boston, 1868).

18

D.

Twelve-Member Juries Fulfilled the

Historical Purpose of the Jury Right.

At common law and at ratification, the jury right

was understood as a guard against tyranny and a

guarantor of liberty. “As John Adams put it, the

founders saw representative government and trial by

jury as ‘the heart and lungs’ of liberty.” Erlinger, 602

U.S. at 829-30 (quoting Letter from Clarendon to

William Pym (Jan. 27, 1766), in 1 Papers of John

Adams 164, 169 (Robert J. Taylor ed., 1977) (“Adams

Papers”)); see also Flowers v. Mississippi, 588 U.S.

284, 293 (2019) (“Other than voting, serving on a jury

is the most substantial opportunity that most citizens

have to participate in the democratic process.”). The

jury was a “guard against a spirit of oppression and

tyranny on the part of rulers”: it was, and remains

today, a “great bulwark of . . . civil and political

liberties.” 2 Story, Commentaries §§ 1779-1780, at

540-41.

In light of this core purpose of the jury, the Sixth

Amendment “carrie[s] with it some meaning about the

content and requirements of a jury.” Ramos, 590 U.S.

at 89. Like the requirement of unanimity this Court

recognized in Ramos, the requirement that a

defendant be convicted by a jury of twelve members is

“[i]nhering” in the constitutional guarantee to a jury

trial. Erlinger, 602 U.S. at 830; see id. at 831 (criminal

charges must be “confirmed by the unanimous suffrage

of twelve” jurors) (emphases added). After all, the

right to trial by jury is “no mere procedural formality,

but a fundamental reservation of power in our

constitutional structure.” Blakely v. Washington, 542

U.S. 296, 305-06 (2004).

19

The authors and defenders of the Constitution

were preeminently concerned with oppression by

majorities: “[T]he majority, having such co-existent

passion or interest, must be rendered, by their

number and local situation, unable to concert and

carry into effect schemes of oppression.” THE

FEDERALIST NO. 10 (James Madison). In the jury

context, this concern is abated by the rule that a jury

must consist of twelve: The greater number provides

greater opportunities for dissenters to put the

government to its proof. See Erlinger, 602 U.S. 829

(without juries, “we ‘have no other fortification . . .

against being ridden like horses, fleeced like sheep,

worked like cattle, and fed and clothed like swine and

hounds’ ”) (quoting Adams Papers at 169) (ellipsis in

Erlinger). For this reason, the drafters were acutely

concerned that “the new federal government might

fall prey to the kinds of temptations that led the

British to restrict the jury trial right in the colonies.”

Id. at 830; see also The Declaration of Independence

paras. 2, 20 (U.S. 1776) (“[t]he history of the present

King of Great-Britain is a History of repeated Injuries

and Usurpations, all having in direct Object the

Establishment of an absolute Tyranny over these

States” by, among other things, “depriving us in many

Cases, of the Benefits of Trial by Jury”).

As Members of this Court have recognized, “a

person in the minority will adhere to his position more

frequently when he has at least one other person

supporting his argument,” a more likely outcome with

twelve than with six or eight. Ballew v. Georgia, 435

U.S. 223, 236 (1978) (plurality opinion). Indeed,

smaller juries were a feature of the Jim Crow era

because they allowed majorities “to suppress minority

voices in public affairs.” Khorrami, 143 S. Ct. at 27

20

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

(citing Ramos, 590 U.S. at 86-89).

And twelve are necessary to safeguard another

guarantee of the Sixth Amendment: that of

impartiality. “The common law required a juror to

have ‘freedome of mind’ and to be ‘indifferent as hee

stands unsworne.’ ” Pena-Rodriguez v. Colorado, 580

U.S. 206, 231 (2017) (Thomas, J., dissenting) (quoting

1 Edward Coke, The First Part of the Institutes of the

Laws of England § 234, at 155a (Dublin, 16th ed.

1809)). A juror at common law was to “have no interest

of their own affected, and no personal bias, or

prepossession, in favor or against either party.” Pettis

v. Warren, 1 Kirby 426, 427 (Conn. Super. Ct. 1788).

Juries of twelve are necessary to achieve this purpose:

“[T]he smaller the group, the less likely it is to

overcome the biases of its members to obtain an

accurate result,” whereas “objectivity result[s]” from

larger groups. Ballew, 435 U.S. at 233 (plurality

opinion). The guarantee of jury impartiality, itself

well-established at common law, is reinforced by the

guarantee of a twelve-member jury. See Parker v.

Gladden, 385 U.S. 363, 366 (1966) (per curiam)

(“[P]etitioner was entitled to be tried by 12, not 9 or

even 10, impartial and unprejudiced jurors.”). Courts

have long recognized that “diminishing the number [of

jurors] impairs the right, lessens the security of the

accused, and increases the danger of conviction,” and,

“[i]f corruption or prejudice are to be feared and

avoided, they are much more likely to influence the

conduct of six [jurors] than of twelve.” Work, 2 Ohio

St. at 305; accord Carpenter, 5 Miss. at 166 (“[A] speedy

public trial by an impartial jury of [the accused’s]

country” is “justly regarded as the palladium of the

personal liberties of the citizen[.]”) (cleaned up).

21

*

*

*

A jury of twelve is required as a matter of text,

history, and tradition. And it fulfills the Constitution’s

aim to effectively deter governmental tyranny and

ensure impartiality. All evidence points in the same

direction: A “jury,” at common law and at the

Founding, was—and remains today—a body of twelve

members.

E.

This Court’s Precedents Recognize the

Original Meaning of “Jury” Is a Body of

Twelve.

Consistent with the historical consensus, in 1898,

this Court spoke unequivocally: “[T]he jury referred to

in the original Constitution and in the Sixth

Amendment is a jury constituted, as it was at common

law, of twelve persons, neither more nor less.”

Thompson, 170 U.S. at 349 (emphasis added). The

Court reiterated this historical understanding in

subsequent years on numerous occasions. See, e.g.,

Capital Traction Co. v. Hof, 174 U.S. 1, 13-14 (1899)

(“the primary and usual sense of the term [‘trial by

jury’] at the common law and in the American

constitutions, is . . . trial by a jury of 12”); Maxwell v.

Dow, 176 U.S. 581, 586 (1900) (“That a jury composed,

as at common law, of twelve jurors was intended by

the Sixth Amendment to the Federal Constitution,

there can be no doubt.”); Rassmussen v. United States,

197 U.S. 516, 527 (1905) (similar); Apprendi, 530 U.S.

at 477 (similar; quoting 4 Blackstone, Commentaries

at 343).

In Ramos, the Court echoed those precedents and

reaffirmed the original public meaning of the Sixth

Amendment: “[A] defendant enjoys a ‘constitutional

22

right to demand that his liberty should not be taken

from him except by the joint action of the court and

the unanimous verdict of a jury of twelve persons.’ ”

590 U.S. at 92 (quoting Thompson, 170 U.S. at 351)

(emphasis added). Most recently, just two years ago in

Erlinger the Court again recognized that a criminal

defendant must be convicted “by the unanimous

suffrage of twelve of his equals and neighbours.” 602

U.S. at 831 (emphasis added; cleaned up). Williams is

in grave tension with those intervening decisions. To

the extent this Court has not already overruled

Williams, it should do so now.

CONCLUSION

For the foregoing reasons, and those set out by

Petitioner, the judgment below should be reversed.

Respectfully submitted,

CECILLIA D. WANG

AMERICAN CIVIL LIBERTIES

UNION FOUNDATION

425 California Street,

Suite 700

San Francisco, CA 94104

BRANDON BUSKEY

PRIYANKA MENON*

AMERICAN CIVIL LIBERTIES

UNION FOUNDATION

125 Broad Street, 18th Floor

New York, NY 10004

DEVI M. RAO

Counsel of Record

RODERICK & SOLANGE

MACARTHUR JUSTICE

CENTER

501 H Street NE, Ste. 275

Washington, DC 20002

(202) 869-3434

devi.rao@macarthurjustice.org

JOHN W. WHITEHEAD

WILLIAM E. WINTERS

THE RUTHERFORD

INSTITUTE

109 Deerwood Road

Charlottesville, VA 22911

23

DANIEL TILLEY

AMERICAN CIVIL LIBERTIES

UNION FOUNDATION

OF FLORIDA

4343 W. Flagler Street

Suite 400

Miami, FL 33134

STUART BANNER

UCLA SCHOOL OF LAW

SUPREME COURT CLINIC

405 Hilgard Ave.

Los Angeles, CA 90095

*Admitted only in Maryland

Counsel for Amici Curiae

AUGUST 2026