Certifying officer powers include receiving evidence, administering oaths, enforcing witness attendance and correcting clerical errors. Certifying officers and the appellate authority have all powers of a civil court to receive evidence, administer oaths, enforce witness attendance, and compel discovery and production of documents, and are deemed civil courts for purposes of specified criminal procedure provisions; clerical or arithmetical mistakes or accidental slips or omissions in orders may be corrected at any time by the officer or a successor.