When the accused in a criminal prosecution is acquitted on the ground that his guilt has not been proved beyond reasonable doubt, a civil action for damages for the same act or omission may be instituted. Such action requires only a preponderance of evidence. Upon motion of the defendant, the court may require the plaintiff to file a bond to answer for damages in case the complaint should be found to be malicious.
If in a criminal case the judgment of acquittal is based upon reasonable doubt, the court shall so declare. In the absence of any declaration to that effect, it may be inferred from the text of the decision whether or not the acquittal is due to that ground.