Alma 54 - 56

Moroni had already come to know a great deal about Ammoron and Amalikiah in that they had headed the insurrection against the government for -

"...Amalickiah was desirous to be a king; and those people who were wroth were also desirous that he should be their king; and they were the greater part of them the lower judges of the land, and they were seeking for power." (Book of Mormon Alma 46:4)

As Moroni raised the Title of Liberty and and came forward to defend their rights and privileges -

"...Amalickiah fled with a small number of his men, and the remainder were delivered up into the hands of Moroni and were taken back into the land of Zarahemla.
34 Now, Moroni being a man who was appointed by the chief judges and the voice of the people, therefore he had power according to his will with the armies of the Nephites, to establish and to exercise authority over them.
35 And it came to pass that whomsoever of the Amalickiahites that would not enter into a covenant to support the cause of freedom, that they might maintain a free government, he caused to be put to death; and there were but few who denied the covenant of freedom." (Book of Mormon Alma 46:33 - 35)

Several years later, as Ammoron leads the armies of the Lamanites against the Nephites, he writes to Moroni -

"...I am Ammoron, the king of the Lamanites; I am the brother of Amalickiah...behold, your fathers did wrong their brethren, insomuch that they did rob them of their right to the government when it rightly belonged unto them." (Book of Mormon Alma 54:16 - 17)

This was the false story that had been passed from generation to generation amongst the Lamanites. Once being a Nephite, Ammoron knew that wasn't true. And again he lies -

"...And as concerning that God whom ye say we have rejected, behold, we know not such a being; neither do ye; but if it so be that there is such a being, we know not but that he hath made us as well as you.
22 And if it so be that there is a devil and a hell, behold will he not send you there to dwell with my brother whom ye have murdered, whom ye have hinted that he hath gone to such a place?..."(Book of Mormon Alma 54:21 - 22)

And then the truth comes out -

I am Ammoron...I am a bold Lamanite; behold, this war hath been waged to avenge their wrongs, and to maintain and to obtain their rights to the government..." (Book of Mormon Alma 54:23 - 24)

It is much like priestcraft in that people will exercise all forms of deception for gain or pride. Moroni though -

"...knew that Ammoron had a perfect knowledge of his fraud..."

I believe that is the case why so many people believe those of deception and priestcraft -

"...because they [are] pleasing unto the carnal mind..." (Book of Mormon Alma 30:53)
(Book of Mormon Alma 55:1)

"...For behold, how much iniquity doth one wicked king [or leader] cause to be committed, yea, and what great destruction...because of their iniquities..." (Book of Mormon Mosiah 29:17 - 18)

Let us be warned -

"...if the time comes that the voice of the people doth choose iniquity, then is the time that the judgments of God will come upon you; yea, then is the time he will visit you with great destruction..." (Book of Mormon Mosiah 29:27)