Narrative: As Mormon reintroduces the growing problem of the Gadianton robbers he must make certain that we understand that the proliferation of this band has nothing to do with the lack of diligence on the part of the record keepers. He has told us that this information had to be kept from the people, so it was not entered into the record that Alma delivered to Helaman. That promise was kept, and the arrival of the Gadiantons is not due to any fault on the part of the record keepers. Rather than a fault of the record keepers, it is directly related to Satan’s influence.
The way that Mormon traces the origin of the Gadianton oaths and secret combinations is important. He begins with Satan, and traces it to the first murder. He does this because he needs to let us know that murder for gain is an important aspect of the Gadianton covenant. Thus he begins the influence with the same being who first suggested a murder for gain in the case of Cain.