Miss. Code § 25-7-47
Witnesses in the county, circuit, chancery and justice courts shall receive the same pay per day as is set by the board of supervisors under Section 25-7-61 for service as a juror plus mileage as authorized under Section 25-3-41 for each mile going to and returning from the courthouse to their homes by the nearest route, and such tolls and ferriages as they may actually be obliged to pay; but a charge shall not be made for mileage except that traveled in this state. Witnesses in all other cases shall receive the same compensation as they receive before the circuit court. It shall not be necessary to issue subpoenas for police officers as witnesses in city cases of cities having a population of more than ten thousand (10,000) according to the federal census of 1930; and officers, when used as witnesses in cases, are not to be allowed witness fees. A law enforcement officer who has retired or otherwise ceased employment as a law enforcement officer but who is required to testify in any case based on matters that arose during the course of the officer's employment shall be entitled to the same compensation and expenses from the former employing law enforcement agency as an officer on active duty under the same circumstances.
Miss. Code § 25-7-47