This is the first time Mormon mentions the name of the man who comes before Alma. Mormon certainly knew the name, but he consciously withheld it until this point.
We cannot be certain of Mormon’s reason, but it is possible that it was withheld for emphasis. The name Nehor will be repeated multiple times as a means of defining a religious movement. It is possible that Mormon saves the name to highlight the nature of the man behind the movement. First he shows the common crimes, and then he gives the name. Thus Mormon’s reader’s understand the evil of the man whose name labels a competing religious movement in Zarahemla.
Social: There are three elements in Nehor’s punishment; place, confession, and death. Each of these has some interesting social implications. First, Nehor is taken to a specific place to be executed. He is taken to the hill Manti. He is not executed immediately, he is not taken to a prison, he is taken to a hill.
With the conceptual meanings associated with hills in most of the ancient world, including both Israel and Mesoamerica, the hill is particularly important. Hills (and other raised places, including the artificial “hills” that were Mesoamerican temples) were locations of sacred significance. There was a closer communication between God and man on a hill.
Thus Nehor, whose crimes were as much religious as they were social, is taken to be closer to God in his last moments.
The second aspect of the execution is the confession. It may be reading too much into the text, but it certainly appears that Nehor’s was not a spontaneous confession. Mormon states: “there he was caused, or rather did acknowledge…” This would suggest that the confession was an important social part of the execution, and was necessary – voluntary or not.
In the context of the times and place, this necessary confession makes a great deal of sense. Note that the confession is very specifically “between the heavens and the earth.” Nehor is on a hill, or on a location “between the heavens and the earth.” This is, or at least can be, a sacred location where the powers of deity are more readily manifest. In this place, Nehor must confess his crimes before God. This provides to all the justification of the actions of the judge. They are righteous, and so attested before God.
The final element is the actual execution. We are told nothing of it except that it is ignominious. We do not know what an ignominious death would have constituted in Nephite thought, but it is clear that there were conceptions of honor and dishonor associated with the mode of death. Nehor is clearly executed in a way that removes personal honor from him.
With a Mesoamerican setting, one might think of multiple modes of death that we moderns would find appalling, such as the removal of the heart of the living man. We would not expect that the Nephites would engage in such practices, but even in other cultures where they were, they were actually a death that conferred honor on the one who was sacrificed. Thus by Mesoamerican conceptions, most of the types of death we associate with those cultures would probably not be the one selected for Nehor.
One possibility of death with dishonor is stoning. Among the later Aztecs it was the punishment for adultery. This was a death of shame. It could have been a mode of death for Nehor, as it would provide the community with an active participation in expressing their communal outrage at his act of shedding blood.
A final note on the execution scene; the final events occur on a hill, and the hill may be visible from many locations. It is also possible that one of the reasons the hill was selected was to increase the visibility to the community.
Such visibility would not only allow the community to vent its feelings, but to serve as a visible warning against similar actions by others in the future (or at least these are the types of reasons given for such public executions).