"And it came to pass that the Nephites...could keep that which was his own, for the thieves, and the robbers, and the murderers...which was in the land." (Mormon 2:10)
"For those who did not belong to their church did indulge themselves in...lying, thieving, robbing, committing whoredoms, and murdering, and all manner of wickedness; nevertheless, the law was put in force upon all those who did transgress it...." (Alma 1:32 )
"...thus, the man was compelled to...be cast out from among the people as a thief and a robber." (Alma 11:2 2)
In the ancient Near Eastern and ancient Israel they did distinguish between thieves and robbers. Particularly with the ancient Israelites and their laws.
Thieves were thought to be local. They stole from their neighbors, and were dealt with judicially, civilly, usually by their neighbors, their townspeople.
Robbers came from the outside and they were a threat to society. They were considered to be outsiders, brigands, and highwaymen. They would organize in groups, they would swear binding oaths; they would extort ransom from the people around them. And when they were caught, they were often caught by the military. This was a military thing, a kind of war. They were dealt with not civilly, but militarily, and they were subject to summary execution. They were dealt quite a differently from thieves.
It is notable that in the Book of Mormon, thieves and robbers are never confused, and robbers, specifically the Gadianton robbers were a national military problem, just as they would have been under ancient Israelite law.
The Book of Mormon is found to be in precise agreement with ancient Near Eastern Israelite concepts, laws and usage.
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"When I would have healed Israel, then the iniquity of Ephraim was discovered, and the wickedness of Samaria: for they commit falsehood; and the thief cometh in, and the troop of robbers spoileth without." (Hosea 7:1)
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Additional Information
What is the Difference Between "Robbers" and "Thieves in the Book of Mormon? (KnowWhy #432) (1:51 min.)
Nephites and the Law of Moses. (Book of Mormon Evidence ) (3:26 min.)
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