In the U. S., a court may overturn a jury verdict of "Guilty" and enter a judgment of acquittal or order a new trial in a criminal case. The basis for such action includes situation where the jury has brough in a verdict that is not supported by the evidence beyond a reasonable doubt. This may happen where a jury is prejudiced against a defendant or makes a mistake in its fact finding or application of the law to the fact after the court jury instruction.
United States Federal Rule of Criminal Procedure 29 states:
(a) Before Submission to the Jury. After the government closes its evidence or after the close of all the evidence, the court on the defendant's motion must enter a judgment of acquittal of any offense for which the evidence is insufficient to sustain a conviction. The court may on its own consider whether the evidence is insufficient to sustain a conviction. If the court denies a motion for a judgment of acquittal at the close of the government's evidence, the defendant may offer evidence without having reserved the right to do so.
(b) Reserving Decision. The court may reserve decision on the motion, proceed with the trial (where the motion is made before the close of all the evidence), submit the case to the jury, and decide the motion either before the jury returns a verdict or after it returns a verdict of guilty or is discharged without having returned a verdict. If the court reserves decision, it must decide the motion on the basis of the evidence at the time the ruling was reserved.
(c) After Jury Verdict or Discharge.
(1) Time for a Motion. A defendant may move for a judgment of acquittal, or renew such a motion, within 14 days after a guilty verdict or after the court discharges the jury, whichever is later.
(2) Ruling on the Motion. If the jury has returned a guilty verdict, the court may set aside the verdict and enter an acquittal. If the jury has failed to return a verdict, the court may enter a judgment of acquittal.
Subsections (b) and (c) make it absolutely clear that a court may set aside a jury verdict of guilty in a criminal case. The Rules do not give the court any authority to set aside a verdict of acquittal.
The reason the FRCP do not permit a court to set aside a jury verdict of acquittal and enter a judgment of guilty is to preserve the Sixth Amendment guarantee that all criminal defendants shall enjoy the right to a trial by jury as well as to preserve the Fifth Amendment prohibition against double jeopardy.
The reason the FRCP permit a trial court to set aside a jury verdict of guilty and enter one of not guilty, is to preserve the defendant's right not to be convicted of a crime except on evidence beyond a reasonable doubt. In the interests of justice, no trial court should let stand a verdict of guilty where the evidence does not prove guilt beyond a reasonable doubt.
These rights apply to state courts as well as to Federal courts because they have been incorporated into the 14th Amendment because they are a fundamental part of our jurisprudence.