A disposition of dismissal is governed by federal and state laws, which vary by state, but generally is a method for a judge to dismiss an legally inadequate indictment, prior to verdict, finding, or plea, in the "interests of public justice".
For example, in one state, the procedures for determining whether the "interests of public justice" warrant a disposition of dismissal in the absence of a trial or a plea are as follows:
"When dismissal of a case is proposed by the defendant or by the judge without the consent of the Commonwealth, the defendant shall file an affidavit in support of a dismissal which shall contain all the facts and the law relied upon in justification of a dismissal. The Commonwealth may file a counter affidavit, and, as to matters contained in the affidavits which are in dispute, there shall be a hearing, unless the judge concludes that on the face of the affidavits 'the interests of public justice' do not warrant a dismissal. If the judge concludes that the 'interests of public justice' require a dismissal he shall record the findings of fact and the reasons for his decision. The Commonwealth would have a right of appeal under G. L. c. 278, § 28E, as amended."