Who was Achan?
Achan was the descendant of Zerah the son of Judah who was put to death, in Joshua's time, for stealing some of the "devoted" spoil of the city of Jericho (Josh 7). The stem Heb: `akhan is not used in Hebrew except in this name.
The stem `akhar has sufficient use to define it. It denotes trouble of the most serious kind--Jacob's trouble when his sons had brought him into blood feud with his Canaanite neighbors, or Jephthah's trouble when his vow required him to sacrifice his daughter (Gen 34:30; Jdg 11:35).
In Prov (11:17,29; 15:6,27) the word is used with intensity to describe the results of cruelty, disloyalty, greed, wickedness. The record especially speaks of Achan's conduct as the troubling of Israel (1 Ch 2:7; Josh 6:18; 7:24). In an outburst of temper Jonathan speaks of Saul as having troubled the land (1 Sam 14:29). Elijah and Ahab accuse each the other of being the troubler of Israel (1 Ki 18:17,18).
The crime of Achan was a serious one. Quite apart from all questions of supposable superstition, or even religion, the Heb: cherem concerning Jericho had been proclaimed, and to disobey the proclamation was disobedience to military orders in an army that was facing the enemy.
It is commonly held that Achan's family were put to death with him, though they were innocent; but the record is not explicit on these points. One whose habits of thought lead him to expect features of primitive savagery in such a case as this will be sure to find what he expects; a person of different habits will not be sure that the record says that any greater cruelty was practiced on the family of Achan than that of compelling them to be present at the execution.
Those who hold that the Deuteronomic legislation comes in any sense from Moses should not be in haste to think that its precepts were violated by Joshua in the case of Achan (see Dt 24:16).
The record says that the execution took place in the arable valley of Achor, up from the Jordan valley.
IBSE, "Isaac" (in the public domain) with minor edits.