Divino Afflante Spiritu (1943) authorized the use of the original texts, which in the case of the Old Testament means chiefly Hebrew.  "Occidere" is a fairly close translation of the Hebrew "ratsach" which means both "kill" and "murder" and derives from a root which means "to cut up." Jerome was not a whiz at Hebrew or Aramaic, but he got it right in his Vulgate with a Latin verb which does some justice to the Hebrew.  The English translation "murder" is narrower than the Hebrew original and the Latin (Vulgate) translation "occidere."