Background
The decision in In re Japanese Electronics, 631 F.2d 1069 (3d Cir. 1980). Critically, the procedural posture of the case was that:
Fourteen of the defendants moved to strike the demands, arguing that
the case is too large and complex for a jury. The district court
denied their motion, concluding that the seventh amendment does not
recognize the complexity of a lawsuit as a valid reason for denying a
jury trial.
The court ultimately held in a 2-1 decision overruling interlocutory order (i.e. mid-case order) the district court allowing a jury trial, that if a case is sufficiently complex, that the due process rights of the defendants to a fair trial overcomes the mutual rights of the parties to a trial by jury in a civil case, and remanded the case to determine if this case was that complex.
This was on the theory that the right to a jury trial in common law lawsuits brought in law rather than equity was not absolute and had certain exceptions, and on the theory that in the event of a conflict between the 5th Amendment right to due process and a fair trial, and the 7th Amendment right to a civil jury trial, that the due process right was stronger.
I don't know how the case was resolved on remand, but I do not believe that this is a majority rule even though this appears to be the law in the 3rd Circuit in federal court (the 7th Amendment right to a jury trial does not apply in state court).
Analysis
could there ever be a criminal case so long and complex (e.g. a
convoluted fraud case) that a jury, guaranteed by the Sixth Amendment,
would be deemed incapable of fully comprehending and considering all
the facts in it? Would it be possible for a future ruling to determine
that a bench trial was required as due process overrides the right to
a jury in a criminal case?
The Sixth Amendment states in the pertinent part that:
"In all criminal prosecutions, the accused shall enjoy the right to a
speedy and public trial, by an impartial jury"
The Sixth Amendment right to a jury trial is definitely one that a criminal defendant can exercise, but the prosecution in a criminal prosecution does not have a corresponding federal constitutional right to a jury trial.
Likewise, the Fifth Amendment right to due process is a right of criminal defendants and not a right of the government prosecuting a case.
So, there are two possibilities. Either the criminal defendant insists upon a jury trial and the prosecution must try to overcome this constitutional right of the defendant, or the criminal defendant insists on a bench trial because the trial is too complex.
If a criminal defendant is insisting on a jury trial, there is no constitutional right of the prosecution to balance against the constitutional rights under the Fifth and Sixth Amendments of the defendant, to use to deny the defendant a jury trial. There is also no historical precedent for there being some kinds of criminal cases in which there is not a right to a jury trial as there was in civil cases at common law (where there were some exceptions to the general rule).
On the other hand, if the criminal defendant wanted to insist on a bench trial due to the complexity of the case, the defendant still have Fifth Amendment due process rights that the defendant can invoke and that the court must honor, while the prosecution has no due process or Fifth Amendment right to a jury trial to balance against that consideration. So, a defendant might be successful in having a very complex criminal case tried before a judge instead of a jury.
Also, it is almost impossible for a criminal trial to be as complex as the complex anti-trust case seeking treble damages in the In re Japanese Electronics case.
If a criminal defendant was facing a very complex case, rather than arguing for a bench trial, the criminal defendant could also seek other remedies to preserve a jury trial and reduce the complexity of the case.
If the criminal case was complex due to the large number of defendants involved, the likely remedy, if a criminal defendant requested it and insisted on a jury trial, would be for a court to order that the case be tried on a defendant by defendant (or small group of defendants by small group of defendants) basis.
Similarly, if a criminal defendant requested it in a highly complex case that is complex because it involves many different incidents, in order to make the case simple enough for a jury to manage, a court might also order the prosecution to limit the number of incidents addressed in each trial to simplify the case (since each incident would normally be a separate count in a criminal indictment that can be tried separately for double jeopardy purposes).
Finally, in federal court and in some states (but not all of them), there is also an institutional barrier to the prosecution bringing a too complex criminal case. This is that cases may only be commenced in that forum with a grand jury's indictment, which wouldn't be possible if a jury couldn't follow what the case involved.
