The commission shall make random field investigations and audits with respect to campaign statements and activity reports filed with the commission under the Nebraska Political Accountability and Disclosure Act. Any audit or investigation conducted of a candidate's campaign statements during a campaign shall include an audit or investigation of the statements of his or her opponent or opponents as well. The commission may also carry out field investigations or audits with respect to any campaign statement, registration, report, or other statement filed under the act if the commission or the executive director deems such investigations or audits necessary to carry out the purposes of the act.