How much does civilian-jury cases impact legal precedent?

Question

Apropos of the Kyle Rittenhouse case:

In the Rittenhouse case, one of the arguments made by the prosecution (I don't know if it was a "main" argument as I only watched snippets of the proceedings myself, but it was definitely presented by the prosecution) is that Kyle Rittenhouse lost his right to self-defence, or at least that right was impacted, by the fact that he chose to be in a plainly dangerous area (a riot zone) in a provocative manner (with a firearm). Therefore, he did not deserve the right to defend himself from a situation that "he caused" (according to the prosecution).

Hypothetically speaking, let's say the civilian jury (whom, to my knowledge, are not law professionals and don't have knowledge of the law beyond what's instructed to them by the judge) agreed with the prosecution in this instance and convicted Rittenhouse based on this notion. The judge, of course, being a trained professional in the law, even if he disagreed with the conviction, would not be able to (to my knowledge) overturn the jury decision and would have to sentence Rittenhouse as guilty.

To what degree could this case, decided by non-legal-professionals, be used as legal precedent in future, similar cases? Could it be used in future cases of life-endangerment (where the defendant believed their life to be in danger), providing the accompanying circumstances (dangerous area + provocative appearance) existed? Could it be used in other cases of attempted capital crime (e.g. where an attempted-rape victim defended themselves and caused grave bodily harm, including death, to the attacker), provided existence of the accompanying circumstances?

Answer 1

A jury verdict does not have any effect as legal precedent.

Only appellate court opinions (that are not mere de novo bench trials of a court not of record) have effect as legal precedent outside the dealings of the actual parties to the case in future litigation with each other. Even then, an appellate court ruling is binding precedent only over the courts inferior to the appellate court issuing the opinion.

Answer 2

Generally only the decisions of judges can create legal precedents. This is because it is only the rationale for a decision which can create a precedent, not the actual decision in a case, and only judges gives reasons - juries don't.

Appellate courts can set precedents. It is also possible for a trial to set a precedent but only if it is a trial by a judge - not a trial by judge and jury.

Answer 3

The judge, of course, being a trained professional in the law, even if he disagreed with the conviction, would not be able to (to my knowledge) overturn the jury decision and would have to sentence Rittenhouse as guilty.

Just to address this bit, but the Judge in the first level trial could actually overturn the Jury by making a Directed Verdict. The Judge can do this at any time during the trial but only to acquit the defendant of a charge or a combination of charges (often called "dismissing the charges"). In fact, there are two times in the trial proper where the Defense can motion for the judge to do so (Upon the prosecution resting AND prior to closing arguments). However, if the jury returns a guilty verdict the judge may give a Directed Verdict (here it's almost always called a Directed Verdict). It cannot be done to overturn an acquittal by the Jury and a Jury acquittal is pretty much always the final word on a trial.

A directed verdict is a finding of law, not of fact (The jury is Finders of Fact, The Judge is Finder of Law) and essentially says that the defendant is Not Guilty by matter of Law, not by matter of fact. A number of examples can demonstrate this, including that the prosecution failed to provide evidence of an element of the crime occurring (in the Rittenhouse trial, the judge dismissed a gun possession charge prior to the jury receiving the case because the specific wording of the law was very vague on whether or not it was applicable to Kyle and when laws are vague the interpretation that benefits the defense will prevail.).

It is very rare for a Directed Verdict being made once the Jury is in deliberations over the verdict as 1.) As the trier of law, the Judge has determined the legal burdens the jury must consider and presented them to the jury in the form of the Jury Instructions, which means the one person who can make a Directed Person is the same person who told the jury how the law is interpeted. 2.) Judges are very reluctant to second guess the jury. 3.) There should have been plenty of time prior to the Jury Deliberations to make the call.

That said, in the specific case of the Rittenhouse trial, there was talk of a post Jury Verdict Directed Verdict if the jury found Rittenhouse guilty. This was due to the fact that during the deliberations, the defense called into question the Prosecutions compliance with disclosure of evidence. At issue was the fact that prosecution may have identified several witnesses but did not identify those to the defense. In addition, critical video evidence provided by the prosecution to the defense was altered to a poorer quality than identical footage that the prosecution used (coupled with an unusual aspect ration in the defense's version of the video, which suggested that the prosecution took steps to not disclose the higher quality footage, which if true, is an error so serious as to end with a mistrial with dismissal of the charges out right).

Overturning the Jury on directed verdict is so rare, that it is one of the few exceptions to Double Jeopardy rule (which in practice prevents the Prosecution from initiating appellant process).