Textual: The beginning of our current chapter doesn’t really make much sense when it is conceptually divorced from the information from the end of our current chapter 6 that those who were forming secret combinations desired a king. Mormon records their desire, but also notes that it did not happen. That statement is a foreshadowing of the next verse. However, it appears to be related to the second phrase, where Mormon tells us that they “did destroy upon the judgment-seat… the chief judge of the land.” These two statements are not really related. The murder of the chief judge was one of the maneuvers by this new secret combination to change the political order so that they could create a king.
Typologically, it is important for Mormon to note the murder of the chief judge, since this has been one of his verifications of the secret combinations. This is what the secret combinations have done. They have sought power, and have sought that power by removing those who were in their way.
Chronological: The thirtieth year would be approximately 26 AD.