Mo. Rev. Stat. § 513.050: Sheriffs and deputies to endorse on execution the time of receipt — rank of writs.

The several sheriffs and their deputies shall, upon the receipt of a writ of execution, without fee for doing the same, endorse thereon the day of the month and year when they receive the same. If two or more writs shall be delivered on the same day, against the same persons, they shall have equal rank, and be executed accordingly.