The Lamanites and the law of Moses

The Nephite authors of the Book of Mormon, sometimes give certain descriptions of the Lamanites that are not exactly flattering. In many cases, they seem to make a point of the Lamanites not following the Law of Moses, which to them is a sign of a people who have strayed from the covenant with God. Some examples:

Jarom 1:6

and they loved murder and would drink the blood of beasts

As mentioned in this post, the consumption of blood was against the Law of Moses. 

Alma 17:15

Thus they were a very indolent people, many of whom did worship idols

In the Old Testament, idol-worshipping was perhaps the very sign of apostasy from the covenant. This was the first of the ten commandments that Moses received.

2 Nephi 5:24

they did become an idle people, full of mischief and subtlety, and did seek in the wilderness for beasts of prey

Beasts of prey were not among the 'clean' animals that were permitted under the Law of Moses. Again, the Nephite authors seem to be making a point about the Lamanites not keeping the Law of Moses.

As a side note, it's tempting to speculate about the original word that has been translated to "subtelty" in the last example, considering the fact that the Hebrew, "arum", means both "subtle" and "naked" and several other passages in the Book of Mormon describing the Lamanites as naked.