The suit when ready for hearing shall be tried at the first term of court, unless good cause for a continuance shall be shown, and in such suit oral evidence given in court of the general reputation of the place or criminal street gang as defined in § 18.2-46.1 shall be admissible for the purpose of proving or tending to prove the existence of such nuisance. If the complaint is filed by a citizen it shall not be dismissed by him before final hearing, except upon a sworn statement made by the complainant and his attorney, setting forth the reasons why the action should be dismissed, and the dismissal approved by the attorney for the Commonwealth, or the Attorney General of the Commonwealth, in writing or in open court. In any case, if the court is of the opinion that the suit ought not to be dismissed, it may direct the attorney for the Commonwealth to prosecute it to judgment; and if the suit is continued more than one term of court, any citizen or the attorney for the Commonwealth may be substituted for the complaining party and prosecute such suit to judgment. If the suit is brought by a citizen, and the court finds there was no reasonable ground or cause for said suit, the costs may be taxed against such citizen.