The accounts addressed the news with the speed of a cable news network. Some adopted the hashtag #guncontrolnow. Others used #gunreformnow and #Parklandshooting. Earlier on Wednesday, before the mass shooting at Marjory Stoneman Douglas High School in Parkland, Florida, many of those accounts had been focused on the investigation by the special counsel Robert Mueller into Russian meddling in the 2016 presidential election.

“This is pretty typical for them, to hop on breaking news like this,” said Jonathon Morgan, chief executive of New Knowledge, a company that tracks online disinformation campaigns. “The bots focus on anything that is divisive for Americans. Almost systematically.”

One of the most divisive issues in the nation is how to handle guns, pitting Second Amendment advocates against proponents of gun control. And the messages from these automated accounts, or bots, were designed to widen the divide and make compromise even more difficult.

Any news event - no matter how tragic - has become fodder to spread inflammatory messages in what is believed to be a far-reaching Russian disinformation campaign. The disinformation comes in various forms: conspiracy videos on YouTube, fake interest groups on Facebook, and armies of bot accounts that can hijack a topic or discussion on Twitter.

Those automated Twitter accounts have been closely tracked by researchers. Last year, the Alliance for Securing Democracy, in conjunction with the German Marshall Fund, a public policy research group in Washington, created a website that tracks hundreds of Twitter accounts of human users and suspected bots that they have linked to a Russian influence campaign.

The researchers zeroed in on Twitter accounts posting information that was in step with material coming from well-known Russian propaganda outlets. To spot an automated bot, they looked for certain signs, like an extremely high volume of posts or content that conspicuously matched hundreds of other accounts.

Florida shooting – in pictures Show all 10 1 /10 Florida shooting – in pictures Florida shooting – in pictures Police arrest a suspect in connection with the shooting at the Marjory Stoneman Douglas High School in Parkland, Florida Reuters Florida shooting – in pictures Parents wait for news after reports of a shooting at Marjory Stoneman Douglas High School in Parkland, Florida AP Florida shooting – in pictures Anxious family members wait for news of students AP Photo/Wilfredo Lee Florida shooting – in pictures Students being evacuated from the school AP Florida shooting – in pictures Students being evacuated from the school Getty Florida shooting – in pictures People gather waiting for word from students AP Florida shooting – in pictures Parents waiting for news on their children AP Florida shooting – in pictures People gather at a hotel where students were taken after the shooting Getty Florida shooting – in pictures Florida Governor Rick Scott speaks to the media as he visits Marjory Stoneman Douglas High School following the shooting AFP/Getty Florida shooting – in pictures Dr. Igor Nichiporenko, Medical Director Trauma, left, and Dr. Evan Boyer, Medical Director, Emergency Services, speak about treating victims and the suspect at a press conference outside Broward Health North hospital AP

The bots are “going to find any contentious issue, and instead of making it an opportunity for compromise and negotiation, they turn it into an unsolvable issue bubbling with frustration,” said Karen North, a social media professor at the University of Southern California’s Annenberg School for Communication and Journalism. “It just heightens that frustration and anger.”