If a judge constructs arguments for the prosecution in judgment is that grounds for appeal?
<p>I recently read a judgment in which the judge constructed arguments that normally one would have expected the prosecution to make. In fact, the defense in the case argued that the prosecutor failed to demonstrate their case by not arguing certain points that they should have. This seemed to create no problem for the judge who just "remedied" the situation by making the arguments that the prosecution should have made in her judgment.</p>

<p>My understanding is that judges are supposed to weigh the merits of the arguments put before them, not make new arguments to repair or strengthen the case for one of the sides. I thought that the judge's tendency to bolster the prosecution's case with such arguments smacked of judicial bias in favor of the prosecution.</p>

<p>Is it grounds for an appeal to complain of judicial bias if a judge makes a de novo argument in their judgement, assuming that argument would have been necessary for a conviction? If so, what are the relevant precedents in United States case law?</p>

<p>(PS is there a technical term for the rules concerning the "role" of the judge in a court, what they supposed to do, and not supposed to do?)</p>

<p>This probably isn't a ground for an appeal.</p>

<p>While a party arguing to reverse a trial court's decision must show that the argument that they are making on appeal was "preserved" by that party at trial by making that argument in the trial court, the converse is not true.</p>

<p>Indeed, one of the rules of appellate practice is that a trial court's ruling will be upheld for any reason supported by the evidence even if it wasn't made by any party at trial.</p>

<p>Generally speaking, a trial court isn't supposed to try a <em>pro se</em> party's case for them, but once the evidence is in, the court is free to do original legal research and come to a conclusions contrary to the arguments made by either of the parties. A judge is supposed to correctly apply the actual law to the facts notwithstanding the efforts of the parties to lead it astray. This doesn't systemically happen in favor of one party or the other in my experience, but is more common when one or both parties is relatively inexperienced in the relevant legal field. </p>

<p>Appellate courts also come to conclusions about the law not advanced by either party on a regular basis.</p>

<p>If anything, this is even more common in the area of administrative law, where the judge is likely to be a subject area specialist, than in ordinary civil litigation. It is also more common in administrative law because a judge in that context is more focused on the institutional implications of a bad precedent than trial court judges in ordinary courts.</p>

<blockquote>
  <p>(PS is there a technical term for the rules concerning the "role" of
  the judge in a court, what they supposed to do, and not supposed to
  do?)</p>
</blockquote>

<p>Probably, but there isn't any term that comes readily to mind. If I can think of one, I will update this answer.</p>

<p>For a civil case there are grounds to appeal for denial of natural justice if the decision is based on grounds that were not raised by the parties.</p>

<p><strong>However,</strong> if the defendant raises an issue which the plaintiff hasn't and by doing so perfects the plaintiff's case, this is something that has been raised and should be considered. It is not uncommon, particularly where a party is unrepresented (although lawyers stuff up too), for them to shoot themselves in the foot like this.</p>

<p>Judges are required to weigh the <em>evidence</em> and apply the relevant law to the dispute. If the parties argue that their dispute is contractual and make no argument about tort or equity, it is not open to the judge to decide on the basis of law not argued. However, if the parties open the door even a little bit, the judge can kick it wide open.</p>

<p>In the inquisitorial system the court is actively involved in investigating the facts of the case. This is distinct from an adversarial system, in which the role of the court is primarily that of an impartial referee between the prosecution and the defense.</p>

united-states civil-procedure judge appeal