Deputy coroner’s, sheriff’s or police officer’s performance of coroner’s duties. If there is no coroner, or it shall appear in like manner that he or she is also a party to or interested in the suit, or of kin, or partial to or prejudiced against either party, or the coroner has an economic or personal interest that conflicts with his or her official duties as coroner, the coroner shall disqualify himself or herself from acting at an investigation or inquest and process shall in like manner issue to the deputy coroner if designated by the coroner to fill the vacancy, or, if no designation is made, to any sheriff, sheriff’s deputy or police officer, in the county, who shall perform like duties as required of the coroner. The designation shall be in writing and filed with the county clerk.