On October 2nd, the news came out that envelopes containing suspected ricin had been mailed to the Pentagon and the White House. We downloaded tweets containing the word "ricin" a few hours after the news broke, resulting in 45007 tweets from 29308 accounts. 
Here's the retweet network for "ricin" on 2018-10-02. It consists almost entirely of right wing accounts, most of which are speculating that the ricin mailing was left-wing terrorism.
We tested a sample of 10000 of the accounts with ricin tweets for automation (based on either 24/7 activity or 90%+ of tweets being posted via automation services/custom apps). 817 (8.2%) were flagged as bots. Let's look at a few of them.
First up: @ColRepubGirl. According to the profile this account is a Republican college student, which is true in whatever universe Republican college students are automated via IFTTT.
What do @ColRepubGirl's automated tweets consist of? There are a lot of media links, almost all of which are to Fox News. The chart of frequently used keywords thus serves more as a profile of Fox content than of this particular account.
Not all of @ColRepubGirl's tweets are links to Fox News. There are some scheduled tweets - for example, the offer to give advice via DM is tweeted every Tuesday. @ColRepubGirl also acknowledges new followers by calling them "conservative comrades".
Next up: @christiabi. This is another bot that presently tweets news links (mostly New York Times), and like @ColRepubGirl has a biography that seems intended to give the impression that the account is human-operated. Perhaps the person pictured is the operator of the account?
We used Google's reverse image search (Tineye is another good option) on @christiabi's profile pic and found a total of 15 Twitter accounts in multiple languages using the same image. There are a few accounts on other social media sites as well.
Here are the timings for the 15 accounts that use the same picture as @christiabi. All of the ones with sufficient tweet volume appear to be automated.
One more bot from the ricin dataset for the road: @SpiritdeCharlie. This is an IFTTT bot that links @PamelaGeller's writing as well as other assorted anti-Muslim fearmongering.
Thanks @ZellaQuixote for research/exploration assistance.
Update: the non-automated 7% of @SpiritdeCharlie appears to have enjoyed this thread.
