1. In addition to the salary provided in sections 57.390^* and 57.400^*, the county commission shall allow the sheriffs and their deputies, payable at the end of each month out of the county treasury, actual and necessary expenses for each mile traveled in serving warrants or any other criminal process at the rate prescribed in this subsection, and actual expenses for each mile traveled, at the rate prescribed in this subsection, in the performance of their official duties in connection with the investigation of persons accused of or convicted of a criminal offense. When mileage is allowed, it shall be computed from the place where court is usually held, and when court is usually held at one or more places, such mileage shall be computed from the place from which the sheriff or deputy sheriff travels in performing any service. When two or more persons who are summoned, subpoenaed, or served with any process, writ, or notice, in the same action, live in the same general direction, mileage shall be allowed only for summoning, subpoenaing or serving of the most remote. The rate for mileage reimbursement pursuant to this section shall be equal to the rate prescribed by the Internal Revenue Service for allowable expenses for motor vehicle use expressed as an amount per mile.

2. At the end of each month, the sheriff and each deputy shall file with the county commission an accurate and itemized statement, in writing, showing in detail the miles traveled by such officer, the date of each trip, the nature of the business engaged in during each trip, and the places to and from which he has traveled. Such statement shall be signed by the officer making claim for reimbursement, verified by his affidavit, and filed by him with the county commission. Whenever claim for reimbursement is made by a deputy, his statement shall also be approved in writing by the sheriff. The county commission shall examine every claim filed for reimbursement, and if found correct, the county shall pay to the officer entitled thereto, the amount found due as mileage.