Amicus Curiae Brief — Mark Todd Minor, Petitioner v. Florida

No. 24-7489

In the

Supreme Court of the United States

MARK TODD MINOR,

Petitioner,

v.

FLORIDA,

Respondent.

On Petition for a Writ of Certiorari to the

District Court of A ppeal of Florida, Fourth District

BRIEF OF STEVEN G. CALABRESI,

SHARI S. DIAMOND, PHOEBE C. ELLSWORTH,

SAMUEL R. GROSS, VALERIE P. HANS,

SAUL KASSIN, STEPHAN LANDSMAN,

RICHARD O. LEMPERT, NANCY S. MARDER,

STEVEN D. PENROD, MARY R. ROSE, AND

MICHAEL J. SAKS AS AMICI CURIAE

IN SUPPORT OF PETITIONER

Stephen R. Senn

Nicholas L. Sellars

Peterson & Myers, P.A.

225 East Lemon Street,

Suite 300

Lakeland, FL 33801

Sarah Lahlou-A mine

Counsel of Record

1032 15th Street NW,

No. 407

Washington, DC 20005

(202) 729-6983

slahlou@probonoinst.org

Counsel for Amici Curiae

120614

A

(800) 274-3321 • (800) 359-6859

i

TABLE OF CONTENTS

Page

TABLE OF CONTENTS . . . . . . . . . . . . . . . . . . . . . . . . . . i

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

INTEREST OF THE AMICI . . . . . . . . . . . . . . . . . . . . . . 1

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

SUMMARY OF ARGUMENT . . . . . . . . . . . . . . . . . . . . . 1

ARGUMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

I.

History of the Twelve-Person Jury . . . . . . . . . . . 3

II. The Functional Equivalence Test and its

Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

III. Current Jurisprudence of Jury Size . . . . . . . . . . 6

CONCLUSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

APPENDIX A — SOURCES . . . . . . . . . . . . . . . . . . . . . 1a

APPENDIX B — AMICI . . . . . . . . . . . . . . . . . . . . . . . . . 3a

ii

TABLE OF CITED AUTHORITIES

Cases:

Page

Apprendi v. New Jersey,

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

Ballew v. Georgia,

435 U.S. 223 (1978) . . . . . . . . . . . . . . . . . . . . . . . . 2, 6, 7

Blakely v. Washington,

542 U.S. 296 (2004) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Khorrami v. Arizona,

143 S. Ct. 22 (2022) . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Opinion of the Justices,

431 A.2d 135 (N.H. 1981) . . . . . . . . . . . . . . . . . . . . . . . 7

Patton v. United States,

281 U.S. 276 (1930) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Ramos v. Louisiana,

590 U.S. 83 (2020) . . . . . . . . . . . . . . . . . . . . . . . . . 2, 4, 8

State v. Hamm,

423 N.W.2d 379 (Minn. 1988) . . . . . . . . . . . . . . . . . . . . 7

Williams v. Florida,

399 U.S. 78 (1970) . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

iii

Cited Authorities

Page

Constitutional Provisions

U.S. Const. amend. VI . . . . . . . . . . . . . . . . . . . . . . . . 1, 2, 4

Rules

Rule 37.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Other Authorities:

Richard S. Arnold, Trial by Jury: The Constitutional

Right to a Jury of Twelve in Civil Trials,

22 Hofstra L. Rev. 1 (1993) . . . . . . . . . . . . . . . . . . . . 3-4

William Blackstone, Commentaries on the Laws of

England (1769) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1

INTEREST OF THE AMICI1

Amici Curiae are university professors whose

teaching and scholarship have addressed historical,

behavioral, and constitutional questions about jury size

and jury performance. Amici are identified in Appendix B.

INTRODUCTION2

We urge the Court to grant certiorari in Minor v.

Florida, No. 24-7489, on the question of whether the Sixth

Amendment permits criminal juries smaller than twelve.

SUMMARY OF ARGUMENT

In Williams v. Florida, 399 U.S. 78 (1970), this Court

mistakenly concluded that by a “jury,” the Framers did

not understand and mean a group of twelve. Having cut

the Sixth Amendment jury-trial requirement free of

its historical mooring, the Court devised a functional

equivalence test to evaluate juries smaller than twelve.

In applying that test, the Court misread existing data

to conclude that six-person juries are functionally equal

to twelve-person juries. Subsequent research confirms

that Williams was built on faulty historical and empirical

foundations.

1. This brief was drafted exclusively by the named amici and

their counsel. Neither party nor their counsel made any monetary

contribution to the preparation or submission of this brief. Counsel

of record for both parties were notified ten days prior to the due

date of this brief of the intention to file this brief in accordance

with Rule 37.2 of the Rules of this Court.

2. Judicial opinions are cited in the text of this Brief; a listing

of selected non-judicial sources appears in Appendix A.

2

In Ballew v. Georgia, 435 U.S. 223, 245 (1978), the

Court effectively abandoned functional equivalence

and—in a fractured set of opinions—offered no coherent

substitute. As a result, there is no consensus among state

courts on what the Court’s jury-size cases mean. See

Khorrami v. Arizona, 143 S. Ct. 22, 23 (2022) (Gorsuch, J.,

dissenting from the denial of certiorari) (“Presently, the

laws in 44 States entitle individuals charged with serious

crimes to a trial before a 12-member jury. Only 6 states .

. . tolerate smaller panels—and it is difficult to reconcile

their outlying practices with the Constitution.”).

In Ramos v. Louisiana, 590 U.S. 83, 99-100 (2020),

the Court rejected a similar functional analysis regarding

the jury unanimity requirement. The Court identified the

meaning of the right to trial by an impartial jury when the

Sixth Amendment was adopted: “the unanimous suffrage

of twelve of [the defendant’s] equals and neighbors[.]” Id.

at 90, 92. The Court rejected efforts to compromise this

“ancient guarantee” under the guise of a “cost-benefit”

analysis. Id. at 100.

The requirement for a twelve-person jury is just as

deeply rooted in the Sixth Amendment as the requirement

for unanimity. Ramos’s reasoning thus applies equally

to the faulty functional analysis of jury size in Williams.

With Ramos illuminating the flawed reasoning on which

Williams was based, this Court should grant certiorari

to review and clarify the constitutional requirements for

the size of state criminal juries.

3

ARGUMENT

I.

History of the Twelve-Person Jury

The seminal modern constitutional case on the size of

state criminal juries, Williams v. Florida, 399 U.S. 78

(1970), inadequately considered the relevant history, and

thereby reached a mistaken conclusion. For more than six

centuries of common law history, a jury was understood

to consist of twelve persons. For nearly two centuries

of U.S. constitutional history, this Court shared that

understanding. For example, in Patton v. United States,

281 U.S. 276, 288 (1930), the Court stated that “it is not

open to question . . . that the jury should consist of twelve

men, neither more nor less.” But the Court departed from

that long-standing and consistent view in Williams, where

the Court reasoned that because the Constitution did not

specify the jury’s size, and because the origins of

twelve were lost in history, no particular number could

be said to have been intended by the Framers.

Historical research into the question since Williams

was decided indicates that the legal culture in which

the authors of the Constitution lived understood

juries to consist inherently of twelve persons. That

understanding was reflected in the Virginia Ratification

Convention, where Madison and others argued that

several characteristics of the jury, including consisting

of twelve members, were “incident to the trial by jury”

and so it was unnecessary to enumerate its attributes in

the Constitution’s text. As Governor Edmund Randolph

explained, “There is no suspicion that less than twelve

jurors will be thought sufficient.” Richard S. Arnold, Trial

by Jury: The Constitutional Right to a Jury of Twelve in

4

Civil Trials, 22 Hofstra L. Rev. 1 (1993) (citing 3 The Debates

in the Several State Conventions on the Adoption of the

Federal Constitution 469 (Jonathan Elliot ed., Philadelphia,

J.B. Lippincott Co. 1836)).

Indeed, in recent cases this Court has repeatedly

recognized that historically the Sixth Amendment

required that “the truth of every accusation . . . should

. . . be confirmed by the unanimous suffrage of twelve

of his equals and neighbours.” Ramos, 590 U.S. at 90

(quoting William Blackstone, Commentaries on the Laws

of England 343 (1769)); Blakely v. Washington, 542 U.S.

296, 301 (2004) (same); accord Apprendi v. New Jersey,

530 U.S. 466, 477 (2000).

II. The Functional Equivalence Test and its

Application

When the Williams Court concluded that twelve jurors

were not required, it devised a test of the constitutionality

of juries of varying sizes: To be constitutional, a

jury must perform as well as the twelve-person unanimous

jury performed. 399 U.S. at 100. This test of functional

equivalence included evaluation of at least the following

dimensions of the jury’s performance: ability to provide

cross-sectional representation of the community, quality

of deliberation, facilitation of dissenters’ resistance to

majority pressure, factfinding accuracy, and verdicts (no

altered advantage to either party). Id. at 100-01.

The Williams Court applied that test to Florida’s

six-person felony juries and concluded that those jury

functions were not “less likely to be achieved when the

jury numbers six, than when it numbers 12[.]” Id. at 100.

5

In the nearly unanimous view of scholars from various

disciplines, the application of the functional equivalence

test in Williams was deeply flawed. In 1970, the Court

had little empirical research from which to draw in

conducting its inherently empirical analysis. What little

it had, it misread or misinterpreted. The opinion cited

studies for propositions opposite to what the studies

found; mistook non-empirical works for empirical findings;

and substituted judicial intuition for well-established

principles of statistical sampling theory.

Consequently, the Court was mistaken in nearly

every empirical conclusion reached along the way to

deciding that six is functionally equal to twelve. Some of

those errors became evident through studies conducted

by researchers whose curiosity was stimulated by the

Williams opinion; other errors should have been apparent

at the time Williams was written.

The most constitutionally significant error in Williams

was the failure to realize that juries of six are substantially

less likely than juries of twelve to contain even a single

member of a minority group. For example, based on

statistical sampling theory, a group that constitutes 10%

of a population would, all else equal, be represented on

72% of twelve-person juries but on only 47% of six-person

juries. The findings of many empirical studies have been

in line with the statistical models. One such study found

that at least one member of a minority group (which

constituted 25.8% of jurors remaining after challenges

were completed) was seated on all but 2% of twelve-person

juries, while 28% of six-person juries contained none of

them at all.

6

Even assuming the Court’s historical analysis was

correct, and that functional equivalence is the proper test

for assessing the constitutionality of a jury’s size, the poor

application of the test in Williams casts a cloud over the

soundness of its holding that six-person criminal juries

are constitutional.

III. Current Jurisprudence of Jury Size

Current jurisprudence governing the constitutionality

of jury size is largely a void. Eight years after inventing the

functional equivalence test, the Court tacitly abandoned

it in Ballew v. Georgia, 435 U.S. 223 (1978). In Ballew

the Court unanimously declared Georgia’s five-person

criminal juries to be below the constitutional minimum,

but none of the four opinions in the case employed the

functional equivalence test to reach that conclusion. Id.

at 245-46.

Justice Blackmun announced the judgment of the

Court in an opinion joined only by Justice Stevens. Id.

That opinion reviewed at length numerous studies and

commentaries which together showed that the factual

conclusions in Williams were empirically and theoretically

mistaken. Id. Bafflingly, however, the opinion relied on

those studies—comparing the performance of six-person

juries to twelve-person juries—to conclude that fiveperson juries are unconstitutional. Id.

Justice Powell, joined by Chief Justice Burger and

Justice Rehnquist, offered no analysis at all, but simply

declared that “a line has to be drawn somewhere.” Id. (If

the line is indeed arbitrary, perhaps it had already been

drawn by the Framers and by history.) Justice Brennan,

7

joined by Justices Stewart and Marshall, concurred in the

judgment but offered no analysis. Id. at 246. Justice White

wrote alone, offering only the unsupported assertion

that a reduction from six to five would violate the crosssection requirement. Id. at 245. (In the Court’s opinion in

Williams, he had concluded, erroneously, that a reduction

from twelve to six would have no effect on cross-sectional

representation.) In sum, the justices abandoned the

functional equivalence test and replaced it with nothing

but incoherence and ipse dixit. Id.

A fter Ballew, there is no longer any coherent

framework for analyzing constitutional jury-size

questions. Not surprisingly, confusion has developed

among state courts. Florida’s courts (e.g., the case at bar)

read Williams to remain good law, despite abandonment

of Williams’s test of constitutionality in Ballew. By

contrast, the supreme courts of Minnesota (State v.

Hamm, 423 N.W.2d 379 (Minn. 1988), superseded by

state constitutional amendment requiring a jury of twelve

for felonies and jury of six for misdemeanors), and New

Hampshire (Opinion of the Justices, 431 A.2d 135 (N.H.

1981)) were persuaded by the factual analysis in Justice

Blackmun’s opinion in Ballew that six-person juries are

not functionally equal to twelve-person juries, and they

so ruled in the jury-size matters before them. Thus, some

state courts have found the dicta of the Court’s jury-size

opinions more illuminating than the holdings. Other

states might adopt various jury sizes and, with no rational

guidance from this Court on how to assess the federal

constitutionality of those juries, confusion will multiply.

8

CONCLUSION

The jury-size cases weave together erroneous

empirical factfinding with mistaken history, producing an

incoherent statement of the law which should be troubling

to legal theorists of various perspectives – originalists,

empiricists, and doctrinalists alike.

The amici urge the Court to grant certiorari and to

overrule Williams in light of Ramos.

Respectfully submitted,

Stephen R. Senn

Nicholas L. Sellars

Peterson & Myers, P.A.

225 East Lemon Street,

Suite 300

Lakeland, FL 33801

Sarah Lahlou-A mine

Counsel of Record

1032 15th Street NW,

No. 407

Washington, DC 20005

(202) 729-6983

slahlou@probonoinst.org

Counsel for Amici Curiae

APPENDIX

i

TABLE OF APPENDICES

Page

APPENDIX A — SOURCES . . . . . . . . . . . . . . . . . . . . . 1a

APPENDIX B — AMICI . . . . . . . . . . . . . . . . . . . . . . . . . 3a

1a

Appendix

A

APPENDIX

A — SOURCES

Albert W. Alschuler & Andrew G. Deiss, A Brief History

of the Criminal Jury in the United States, 61 U. Chi. L.

Rev. 867 (1994).

American Bar Association, American Jury Project,

Principles for Juries and Jury Trials (2023).

Richard S. Arnold, Trial by Jury: The Constitutional

Right to a Jury of Twelve in Civil Trials, 22 Hofstra L.

Rev. 1 (1993).

Shari Seidman Diamond, Destiny Peery, Francis J. Dolan

& Emily Dolan, Achieving Diversity on the Jury: Jury

Size and the Peremptory Challenge, 6 J. Empirical Legal

Stud. 425 (2009).

Valerie P. Hans, The Power of Twelve: The Impact of Jury

Size and Unanimity on Civil Jury Decision Making, 4

Del. L. Rev. 1 (2001).

Richa rd Lemper t , Uncover ing ‘Non discer nible’

Differences: Empirical Research and the Jury-Size Cases,

75 Mich. L. Rev. 643 (1975).

G. Thomas Munsterman, Janice T. Munsterman & Steven

Penrod, A Comparison of the Performance of Eight- and

Twelve-Person Juries (1990).

Michael J. Saks, The Smaller the Jury, the Greater the

Unpredictability, 79 Judicature 263 (1996).

2a

Appendix A

Michael J. Saks & Mollie Weighner Marti, A MetaAnalysis of the Effects of Jury Size, 21 Law & Hum.

Behav. 451 (1997).

Alisa Smith & Michael J. Saks, The Case for Overturning

Williams v. Florida and the Six-Person Jury: History,

Law, and Empirical Evidence, 60 Fla. L. Rev. 441 (2008).

Nicole L. Waters, Does Jury Size Matter? A Review of

the Literature (Nat’l Ctr. State Cts., 2004).

Hans Zeisel, . . . And Then There Were None: The

Diminution of the Federal Jury, 38 U. Chi. L. Rev. 710

(1971).

Hans Zeisel & Shari S. Diamond, “Convincing Empirical

Evidence” on the Six Member Jury, 41 U. Chi. L. Rev.

281 (1974).

3a

APPENDIX

Appendix

B —BAMICI

Steven G. Calabresi, JD, Clayton J. and Henry R. Barber

Professor of Law, Northwestern University Pritzker

School of Law.

Shari S. Diamond, JD, PhD, Howard J. Trienens Professor

of Law and Professor of Psychology, Northwestern

University Pritzker School of Law.

Phoebe C. Ellsworth, PhD, Frank Murphy Distinguished

University Professor Emerita of Law and Psychology,

University of Michigan Law School.

Samuel R. Gross, JD, Thomas and Mabel Long Professor

of Law Emeritus, University of Michigan Law School.

Valerie P. Hans, PhD, Charles F. Rechlin Professor of

Law, Cornell Law School.

Saul Kassin, PhD, Distinguished Professor, John Jay

College of Criminal Justice, The City University of New

York.

Stephan Landsman, JD, Emeritus Professor of Law and

Organizer and Director, Clifford Symposium on Tort Law

and Social Policy Emeritus, DePaul College of Law.

Richard O. Lempert, JD, PhD, Eric Stein Distinguished

University Professor Emeritus of Law and Sociology,

University of Michigan.

4a

Appendix B

Nancy S. Marder, JD, Professor of Law and Director of

the Justice John Paul Stevens Jury Center, Chicago-Kent

College of Law.

Steven D. Penrod, JD, PhD, Distinguished Professor, John

Jay College of Criminal Justice, The City University of

New York.

Mary R. Rose, PhD, Professor, Department of Sociology

and Director, Human Dimensions of Organizations

Program, University of Texas at Austin.

Michael J. Saks, PhD, MSL, Regents Professor,

Sandra Day O’Connor College of Law and Department

of Psychology, Arizona State University.