It's not irrelevant. What's most immediately relevant, however, is whether the judge thinks innocence is so clear that no reasonable jury could convict. In such

It's not irrelevant. What's most immediately relevant, however, is whether the judge thinks innocence is so clear that no reasonable jury could convict. In such a case the judge is obliged to declare a mistrial or enter an aquittal. The technical way to put this is that innocence is always presumed, and the judge has the final say over whether guilt has been adequately proven. It gets lost amidst a mountain of doctrine and procedure, but even in Common Law systems one of the principal functions of a trial, and the judicial office generally, is establishing the truth, just as in continental European systems. Trial procedure is primarily adversarial, but judges absolutely have the power to independently seek the truth. One of the most common ways this manifests in a jury trial is the judge directly posing questions to witnesses. (Judges don't habitually ask questions as merely posing questions could potentially prejudice a defendant--who may be, for example, strategically avoiding some subject matter--and especially in a jury trial judges must be careful to maintain the appearance of impartiality so as not to influence or lose the faith of juries.) Because in Common Law systems investigative and prosecutorial powers are typically held and executed by another branch of government (or at least another party, public or private), judicial discretion naturally tends to be confined to courtrooms. But historically, and today even in many rural areas with limited government services, judges' roles can be more expansive, fundamentally deriving from their function of establishing the truth. EDIT: A legal note on Federal Rules of Evidence 614 (Calling and Interrogation of Witnesses by Court) I put together many years ago for my Evidence class: https://25thandClement.com/~william/Evidence/614.pdf https://25thandClement.com/~william/Evidence/614.pdf For the broader principle at play, see footnote 2 citing the most eminent American scholar of Evidence, John Wigmore, as saying that courts have a duty to "to elicit the truth more fully"; and the statesman Edmund Burke arguing even more broadly that, "A Judge is not placed in that high situation merely as a passive instrument of parties: He has a duty of his own, independent of them, and that duty is to investigate the truth."