(1) The county attorney or authorized attorney, upon referral from the Department of Health and Human Services, shall file a complaint to modify a child support order unless the attorney determines in the exercise of independent professional judgment that:
(a) The variation from the Supreme Court child support guidelines pursuant to section 42-364.16 is based on material misrepresentation of fact concerning any financial information submitted to the attorney;
(b) The variation from the guidelines is due to a voluntary reduction in net monthly income. For purposes of this section, a person who has been incarcerated for a period of one year or more in a county or city jail or a federal or state correctional facility shall be considered to have an involuntary reduction of income unless (i) the incarceration is a result of a conviction for criminal nonsupport pursuant to section 28-706 or a conviction for a violation of any federal law or law of another state substantially similar to section 28-706, (ii) the incarcerated individual has a documented record of willfully failing or neglecting to provide proper support which he or she knew or reasonably should have known he or she was legally obligated to provide when he or she had sufficient resources to provide such support, or (iii) the incarceration is a result of a conviction for a crime in which the child who is the subject of the child support order was victimized; or
(c) When the amount of the order is considered with all the other undisputed facts in the case, no variation from the criteria set forth in subdivisions (1)(a) and (b) of section 43-512.12 exists.
(2) The department, a county attorney, or an authorized attorney shall not in any case be responsible for reviewing or filing an application to modify child support for individuals incarcerated as described in subdivision (1)(b) of this section.
(3) The proceedings to modify a child support order shall comply with section 42-364, and the county attorney or authorized attorney shall represent the state in the proceedings.
(4) After a complaint to modify a child support order is filed, any party may choose to be represented personally by private counsel. Any party who retains private counsel shall so notify the county attorney or authorized attorney in writing.