Concept
Jury Size
Selection and composition of juries
Jury Size
A federal civil jury need not have twelve members. Rule 48(a) requires a jury to begin with at least 6 and no more than 12 members, and it requires each juror to participate in the verdict unless excused under Rule 47(c).1 Twelve survives as the ceiling, and many cases are now tried to juries of as few as six.2 An answer that assumes twelve jurors in every federal civil trial misstates the rule.
Three sources of law bear on the number, and they rank. The Constitution is the “supreme Law of the Land,” and the Seventh Amendment’s guarantee of jury trial in certain civil cases limits what Congress, the Supreme Court, and the districts may do with the civil jury.3 The Federal Rules come next. Beneath them sit the local rules of each district court, which must be consistent with the Federal Rules, federal statutes, and the Constitution.4 When two sources conflict, the higher one controls.
The three subsections that follow move through that ranking. The first reads Rule 48(a) itself. The second turns to the Seventh Amendment and explains why a jury of six satisfies it. The third tests a district’s local rule on jury size against the Rule above it.
Rule 48(a) Size Limits
Rule 48(a) fixes two numbers and one moment. The floor of six and the ceiling of twelve both apply when the jury begins, and the participation clause makes the jurors seated at the start the jurors who decide, with excusal under Rule 47(c) as the stated exception.5 The Rule leaves open the number between the floor and the ceiling.
The case for a smaller jury is speed. Smaller juries should be selected more rapidly, and their deliberations should be shorter simply because there are fewer individual opinions to consider.6 Even in federal civil cases, the Seventh Amendment does not require a twelve-member jury, and the number of jurors in state trials varies from state to state.7 The next subsection explains why the amendment permits the smaller number.
The Rule speaks of how the jury begins because a jury can shrink before it decides. The court seats the jury before any evidence is heard, and jurors may leave at any point before the verdict. A minimum measured only at the start would protect nothing if the jury could dwindle before deliberations, so the count that matters is the count at verdict. Federal courts therefore normally seat more than six jurors, so that if some have to leave the panel, at least six remain when the verdict is returned.8 Each juror seated above six absorbs one departure: a jury of eight can lose two and still reach six, and a jury of twelve can lose six.
The cushion has a limit. If fewer than six jurors remain at the time of verdict, the court must declare a mistrial unless both parties agree to continue.9 Rule 48(a) gives a court no authority to begin with fewer than six, so the parties’ agreement matters only after the jury has fallen below six.10
Both courts complied with Rule 48(a) when they swore their juries, and the cushion alone explains the different outcomes. The six-member jury was lawful at the start but left no margin, while the ten-member jury could lose four and still reach six. The common error is to treat twelve as required, which misreads a ceiling as a command. The question that decides these problems is how many jurors remain when the verdict is returned, because fewer than six, without both parties’ agreement, ends in a mistrial.
Colgrove and the Seventh Amendment
The Seventh Amendment stands above Rule 48(a), and its text says nothing about the number of jurors. It provides: “In Suits at common law, where the value in controversy shall exceed twenty dollars, the right of trial by jury shall be preserved, and no fact tried by a jury, shall be otherwise reexamined in any Court of the United States, than according to the rules of the common law.”13 A Rule that lets a civil jury begin at six therefore raises the question whether the preserved right includes a jury of twelve. In Colgrove v. Battin, the Supreme Court held that a jury of as few as six is permissible under the Seventh Amendment.14
Two features of the amendment frame the question. First, the word preserved is measured against English practice: the Court said in Baltimore & Carolina Line v. Redman that the preserved right is the one that “existed under the English common law when the amendment was adopted.” Under this historical test, a court considers practice in the courts of law and equity in England in 1791 to decide whether a claim goes to a jury today.15 Second, the amendment governs only federal trials. As Walker v. Sauvinet put it, the amendment “relates only to trials in the courts of the United States,” and the States “are left to regulate trials in their own courts in their own way.” Most states guarantee jury trial anyway, often in terms that closely mirror the Seventh Amendment, and state court decisions on the point usually turn on state constitutional provisions.16
The historical baseline is what makes the size question hard. The traditional civil jury had twelve members, and if the amendment froze the jury as it stood in 1791, twelve would be part of the right itself and every federal court that seated fewer civil jurors would be violating the Constitution.17 The question was live because federal district courts had begun adopting local rules that authorized six-person civil juries, and the petitioner in Colgrove argued that the amendment requires twelve.18 The stakes reached rulemaking generally, because the statute that authorizes the Supreme Court’s procedural rules directs that they “shall preserve the right of trial by jury as at common law and as declared by the Seventh Amendment to the Constitution.”19
The Court answered by separating the substance of the right from the machinery that once delivered it. What must be preserved is “the substance of the common-law right of trial by jury, as distinguished from mere matters of form or procedure.” The amendment therefore does not “bind the federal courts to the exact procedural incidents or details of jury trial according to the common law in 1791,” and “[n]ew devices may be used to adapt the ancient institution to present needs and to make of it an efficient instrument in the administration of justice.”20 A reading that froze every 1791 detail would bar adjustments to a procedure that had proved costly, while a reading that protects only the substance keeps the guarantee and leaves room to adjust the machinery. Whether the number of jurors is machinery or substance depends on what the number does for the jury.
The Court found its test in a criminal case. In Williams v. Florida, it held that a six-person jury in a state criminal trial satisfied the Sixth Amendment, because the inquiry turns on the function a feature performs and its relation to the purposes of jury trial.21 The function the Court had in view was the common-sense judgment of a group of laypeople, and it found that a group of six differs little from a group of twelve in representing a cross-section of the community.22 Colgrove carried that premise into civil cases: the twelve-member panel is not a substantive aspect of the jury-trial right.23
The reasoning that permits six jurors does not settle every civil-jury question. The Court has not decided whether the Seventh Amendment requires unanimous civil verdicts, because Rule 48(b) already requires them, and a later section of this chapter takes up unanimity.24
The function test also draws a lower boundary, because a jury that shrinks must still be able to do a jury’s work. In Ballew v. Georgia, the Court held that a conviction returned by a five-member jury violated the Sixth Amendment.25 By analogy, a five-person civil jury should violate the Seventh Amendment.26 That conclusion is an inference from a criminal decision and not a civil holding, and an exam answer should say so. The firmer footing is Rule 48(a), which requires a jury to begin with at least six.27 The floor in the Rule and the probable constitutional floor coincide at six.
The two plaintiffs lose for different reasons, and the difference is what exam stems on this topic usually probe. A federal civil jury is tested against the Seventh Amendment, and because six jurors are enough, the objection that twelve are required is the wrong one to raise. A state civil jury is not tested against the amendment at all, because the States are left to regulate trials in their own courts.28 The usual error is to carry the number twelve into either setting as though history had made it a constitutional command.
Local Rules on Jury Size
Rule 48(a) answers the size question for every federal civil trial, but each district court still writes local rules for the details of practice in that district, and those rules must be consistent with the Federal Rules, federal statutes, and the Constitution.32 A local rule on jury size therefore raises a question the earlier subsections did not: whether the district has filled a space the Rule leaves open or has changed something the Rule already decided.
One principle governs each step down the hierarchy: a lower source may supplement the sources above it but may not contradict them. The Seventh Amendment shows both halves. Congress could not enact a statute barring jury trial in the cases the amendment covers, yet Congress may enact statutes that regulate procedure in the federal courts in ways consistent with the Constitution.33 The Federal Rules rest on delegated power, since the Rules Enabling Act authorizes the Supreme Court to adopt rules for practice in the federal district courts, and the statute directs that those rules preserve the right of trial by jury.34 Rule 83 gives each district a narrower power. A majority of a district’s judges may make rules governing its practice “not inconsistent with these rules,” and in cases “not provided for by rule” the court may regulate its practice in any manner not inconsistent with them.35
Each half of the principle does separate work. Permission to supplement lets a district decide matters the higher sources leave open. The bar on contradiction keeps a Rule uniform where it speaks, so that it does not mean one thing in one district and another thing in the next.
Local rules on jury size are an ordinary feature of federal practice. In the second half of the twentieth century, federal district courts began adopting local rules that authorized six-person civil juries, and Colgrove held such juries permissible under the Seventh Amendment.36 That decision cleared the constitutional layer for rules of that kind. The wording of Rule 48 quoted in the Colgrove opinion differs from today’s, because it let the parties stipulate to a jury of any number less than twelve.37 A modern local rule is measured against the current six-to-twelve text.38
The two provisions get opposite results because each does something different to Rule 48(a). Choosing eight fits inside the range and changes no requirement, since the Rule fixes a floor and a ceiling and leaves the number between them open.39 The dismissal provision acts on something the Rule has already decided. Because each juror must participate in the verdict unless excused under Rule 47(c), excusal is the only route by which a seated juror leaves the deliberating group, and a provision that dismisses two jurors who were never excused creates a second route the Rule does not contain.40
That six jurors remain does not rescue the dismissal provision. Six is a permissible number at verdict, so the objection concerns how the jury got to six. The participation clause makes the jury that begins the jury that decides, and the cushion above six exists to absorb departures that occur through excusal during trial. A local rule that spends the cushion on a schedule uses up in advance the margin that protects the verdict floor. Because each provision is compared with the Rule on its own, the objecting party loses on the number and wins on the dismissal clause.
The same comparison sorts other local choices. A rule fixing civil juries at six, ten, or twelve fits the range, while a rule fixing them at five or at fourteen contradicts the floor or the ceiling in Rule 48(a), and the five-member version would also draw the Seventh Amendment objection discussed above.41 An exam stem describing a local rule on jury size is usually built from provisions that must be sorted, and the sorting question is whether each provision picks something the Rule leaves open or changes something the Rule imposes.