Wyo. Stat. Ann. § 14-3-411

Complaints alleging a child is neglected shall be referred to the office of the district attorney. The district attorney shall determine whether the best interest of the child requires that judicial action be taken. The department of family services and the county sheriff shall provide the district attorney with any assistance he may require in making an investigation. The district attorney shall prepare and file a petition with the court if he believes action is necessary to protect the interest of the child.