Can the Jury Conduct Experiments?
Normally courts take great pains to avoid thinking about how jurors reach their decisions. For example, the aliunde rule, observed in many jurisdictions, states that a jury verdict cannot be challenged based upon a juror’s testimony. [1] So even if a juror comes forward and says, “I have to confess – we were all drunk and high when we convicted that guy,” that testimony will not suffice to overturn a verdict. Lest you think I’m exaggerating for effect, consider Tanner v. United States, where the United States Supreme Court refused to overturn a jury verdict despite the following testimony from a juror, Daniel Hardy:
Hardy indicated that seven of the jurors drank alcohol during the noon recess. Four jurors, including Hardy, consumed between them “a pitcher to three pitchers” of beer during various recesses. Of the three other jurors who were alleged to have consumed alcohol, Hardy stated that on several occasions he observed two jurors having one or two mixed drinks during the lunch recess, and one other juror, who was also the foreperson, having a liter of wine on each of three occasions. Juror Hardy also stated that he and three other jurors smoked marijuana quite regularly during the trial. Moreover, Hardy stated that during the trial he observed one juror ingest cocaine five times and another juror ingest cocaine two or three times. One juror sold a quarter pound of marijuana to another juror during the trial, and took marijuana, cocaine, and drug paraphernalia into the courthouse. Hardy noted that some of the jurors were falling asleep during the trial, and that one of the jurors described himself to Hardy as “flying.” [2]
But occasionally a jury will get up to hijinks that simply cannot be ignored. And courts are reluctantly forced to craft rules concerning what hijinks are sufficient to warrant a new trial.
One example of “juror hijinks policing” is the law of jury experimentation. Courts normally exercise careful control over what sort of scientific findings can be admitted into evidence, excluding experimental results that are based upon faulty reasoning or flawed design. Since most jurors are not scientists and their deliberations are not subject to any such standards, juries are often specifically instructed not to run their own “experiments” to try to “figure out what really happened.” [3]
But as the California Supreme court has noted, this categorical instruction is not rigidly enforced as a matter of practice. Instead, “jury experiments” are typically analyzed under the rubric of “extrinsic evidence.” An experiment “that results in the acquisition of new evidence” is forbidden, but one that “is simply a more critical examination of the evidence admitted” is not. [4] The reason usually given is parties have the right to challenge and cross examine any evidence presented in a case, but that mere scrutiny and examination of existing evidence, even if it takes the form of an experiment, does not give rise to such a right.
At first blush, this might sound like a meaningful distinction, but it’s not clear how well it holds up under scrutiny. Any experimental result offered by a party, whether a lab test, a fingerprint analysis, or an accident reenactment would be treated as potential “evidence” by the court and, if admitted at all, would be subject to challenge and cross examination. And juries are repeatedly instructed to only base their verdicts upon admitted evidence, not anything else. So, the idea that the jury can run an experiment, generate a “non-evidence” result not reviewed or challenged by anyone and then base its verdict on that “non-evidence” result seems highly dubious.
Because the rule is a bit weird, it leads to some unusual and somewhat arbitrary results. For example, in Melgar v. State [5]a defendant was accused of murdering her husband and staging his body to make it appear that there had been a home invasion. The body was found bound with telephone cords, but the state claimed that they had been tied only after death. In deliberations, many of the jury members participated in experiments where they tied themselves up to see if it was possible to escape from restraints – in effect to test whether the body had been staged. Nevertheless, the court held that the jury “did not discovery any new fact in their experiments” and sustained the guilty verdict. [6]
In contrast, in Jennings v. Oku [7] jurors considered a murder case where only a single fingerprint on a car door tied the defendant to the crime scene. The prosecution argued that the fingerprint was placed during an attack. But the defendant claimed that the fingerprint was left when he opened the door to steal the (already-murdered) victim’s wallet. To sort the matter out, the jurors decamped for the parking lot, where they experimented on the jury foreperson’s car, trying to try to re-enact both versions of events. On federal habeas review, the court overturned the guilty verdict, finding that the reenactments constituted “extrinsic evidence” improperly considered by the jury. [8]
But other reenactments by a jury are frequently permitted. For example, in People v. McBayne, a court rejected a challenge based on reenactments during deliberations, specifically holding that “[a] jury may conduct a demonstration of the crime in the jury room provided it involves no more than the jurors’ application of everyday experiences, perceptions and common sense to the evidence.” [9] Similarly, in United States v. Abeyta, the Tenth Circuit rejected a challenge to a conviction based on re-enactments of a stabbing in the jury room, for which one of the jurors somehow smuggled his own pocket knife into the courthouse. [10]
How do we reconcile these cases? While theoretically applying a similar legal rule – “no outside evidence” – the cases can largely be explained by a few unstated rules of thumb.
First, almost any experiment is fine, so long as it takes place entirely within the jury room, does not rely upon outside materials and all the jurors are involved. Juror reenactments that take place in the courthouse are rarely challenged, and so long as jurors are playing around with admitted evidence or materials that they can find in a courthouse, courts are highly unlikely to overrule a verdict. In the rare case where experiments in the jury room have been successfully challenged, it has largely been where truly exotic materials were smuggled in by jurors. For example, in Smoketree-Lake Murray, Ltd. v. Mills Concrete Constr. Co., [11] a jury considered a fraud case involving defective construction in a residential condominium complex. One of the jurors somehow brought kitty litter and crayons into to the jury room to conduct a “demonstration” for the rest of the jury concerning how concrete is poured and how defects can form. On review, the court threw out the verdict, finding that the bizarre experiment constituted “new evidence.”
Second, where an experiment is conducted by less than the full jury and takes place outside the courtroom, courts are more willing to disturb a subsequent verdict. For example, in In re Beverly Hills Fire Litigation [12] a fire destroyed a private club and killed 165 people. The plaintiffs, next of kin to the deceased, contended that defective wiring was responsible and sued the wiring manufacturers. One of the jurors took it upon himself to disassemble the wiring in his own home at night to see if it resembled the wiring at issue. He then reported his findings to the rest of the jury. On review, the Sixth Circuit threw out the subsequent verdict, finding that this experiment constituted “evidence not offered at trial.” [13] Similarly, in People v. Legister, a juror conducted an experiment in her hotel room to ascertain whether a trial witness could actually have identified someone in the dark. The New York Court of Appeals threw out the verdict, finding that this experiment constituted “nonrecord evidence not subject to challenge by the defendant.” [14]
What can we take away from all of this? Watch what you send into the jury room! If there is a physical piece of evidence in a case, think long and hard before you permit it to be sent in for jury deliberations. And if a piece of evidence is sent in, consider requesting a specific instruction from the judge that it is not to be used for new experimentation. Otherwise, if you aren’t careful, you might just see a verdict go sideways based upon “scientific evidence” that you never saw coming.
[1] In the Federal system, this is embodied in Fed. R. Evid. 606, but also appears in states, like New York, that have not mirrored the federal rules. Depending on the jurisdiction there are some limited exceptions, though substantially fewer than you might think.
[2] Tanner v. United States, 483 U.S. 107, 115–16 (1987) (internal cites omitted).
[3] For example, in California CACI 100 instructs jurors “Do not investigate the case or conduct any experiments.”
[4] People v. Collins, 49 Cal. 4th 175, 244 (2010).
[5] 593 S.W.3d 913 (Tex. App. 2020).
[6] Id. at 923-24.
[7] 677 F.Supp. 1061 (D. Hawaii 1988).
[8] Id. at 1065.
[9] 204 A.D.3d 549 (1st Dep’t 2022).
[10] 27 F.3d 470, 477 (10th Cir. 1994).
[11] 234 Cal. App. 3d 1724 (Cal. App. 1991)
[12] 695 F.2d 207 (6th Cir. 1982).
[13] Id. at 215.
[14] 75 N.Y.2d 832 (1990).
