I think that the take-home point in the bots’ role in the shooting story is similar to the current state of politics on the federal level.
In addition to feeding all of the right wing sites their propaganda conspiracy stories and lies, the bots also maintain a constant level of divisiveness in the American public. They are trying to incite hatred and tribalism, so that the democracy cannot come to agreement on many many issues. They succeed wildly on the right, and to some degree they even succeed on the left.
While the common sense and reasonable response to multiple horrific school shooting is to step up prevention of dangerous people getting guns, etc.... which the large majority of American citizens (of all political ideologies) agree with. The bots stoke up the crazy 20% of the NRA uber-zealots into thinking that
any regulation of guns in the US would lead directly to anarchy, death, and the apocalypse. (see LaPierre’s crazy pre-emptive rant/speech about Parkland; Congresswoman Tenney’s comments about mass murderers being democrats; or this bull about “crisis actors” and “false flags”).
These conned suckers get loud enough, and no reasonable action will be taken.