A law enforcement agency that is notified by affidavit of an alleged violation of this chapter shall promptly investigate. Upon receiving an affidavit alleging a violation of this chapter, a county attorney shall promptly forward it to a law enforcement agency with jurisdiction for investigation. If there is probable cause for instituting a prosecution, the county attorney shall proceed by complaint or present the charge, with whatever evidence has been found, to the grand jury. A county attorney who refuses or intentionally fails to faithfully perform this or any other duty imposed by this chapter is guilty of a misdemeanor and upon conviction shall forfeit office. The county attorney, under the penalty of forfeiture of office, shall prosecute all violations of this chapter except violations of this section; if, however, a complainant withdraws an allegation under this chapter, the county attorney is not required to proceed with the prosecution.