La. Stat. tit. 15 § 252
Witnesses subpoenaed in all preliminary criminal trials or proceedings, for attendance before grand juries and upon final trials shall receive a per diem of three dollars per day and mileage of not more than five cents for each mile necessarily traveled in going to and returning from court, the exact amount to be fixed by the police juries of the several parishes, provided, however, that in the parishes of Acadia and Vermilion witnesses shall not be allowed any fees, per diem or mileage in all preliminary criminal trials or proceedings and for attendance before grand juries, provided further, however, that witnesses subpoenaed in the parishes of Acadia and Vermilion upon final trials shall receive a per diem of three dollars per day and mileage of not more than five cents for each mile necessarily travelled in going to and returning from court, the exact amount to be fixed by the police juries of the parishes of Acadia and Vermilion.
La. R.S. § 15:252