Before issuing a warrant, the judge so issuing, or the Clerk, may, if either of them deems it necessary, require the complainant to enter into bond with sufficient surety to the City, conditioned for the appearance of the complainant at the trial, to give evidence against the person complained of by him or her, and if upon the trial the defendant shall be discharged, that the complainant shall pay the costs of prosecution, if so ordered by the Court. In all cases, whether a bond is taken or not, when the defendant is acquitted, the informant or complainant may be adjudged to pay the costs, if it appears to the Court that the prosecution was instituted vexatiously, maliciously or without probable cause.