SAN FRANCISCO — One hour after news broke about the school shooting in Florida last week, Twitter accounts suspected of having links to Russia released hundreds of posts taking up the gun control debate.
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, Fla., many of those accounts had been focused on the investigation by the special counsel Robert S. Mueller III 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.”
When the Russian bots jumped on the hashtag #Parklandshooting — initially created to spread news of the shooting — they quickly stoked tensions. Exploiting the issue of mental illness in the gun control debate, they propagated the notion that Nikolas Cruz, the suspected gunman, was a mentally ill “lone killer.” They also claimed that he had searched for Arabic phrases on Google before the shooting. Simultaneously, the bots started other hashtags, like #ar15, for the semiautomatic rifle used in the shooting, and #NRA.
The bots’ behavior follows a pattern, said Mr. Morgan, one of the researchers who worked with the German Marshall Fund to create Hamilton 68, the website that monitors Russian bot and fake Twitter activity. The bots target a contentious issue like race relations or guns. They stir the pot, often animating both sides and creating public doubt in institutions like the police or media. Any issue associated with extremist views is a ripe target.
The goal is to push fringe ideas into the “slightly more mainstream,” Mr. Morgan said. If well-known people retweet the bot messages or simply link to a website the bots are promoting, the messages gain an edge of legitimacy.
An indictment made public on Friday by Mr. Mueller as part of the investigation into Russian interference in the election mentioned a Russian Twitter feed, @TEN_GOP, which posed as a Tennessee Republican account and attracted more than 100,000 followers. Messages from this now-deleted account were retweeted by the president’s sons and close advisers including Kellyanne Conway and Michael T. Flynn, the former national security adviser.
The indictment also described how fraudulent Russian accounts on Twitter tried to push real Americans into action. The indictment said the fake Twitter account @March_for_Trump had organized political rallies for Mr. Trump in New York before the election, including a “March for Trump” rally on June 25, 2016, and a “Down With Hillary” gathering on July 23, 2016.
By Friday morning, the bots that pushed the original tweets around the Parkland shooting had moved on to the hashtag #falseflag — a term used by conspiracy theorists to refer to a secret government operation that is carried out to look like something else — with a conspiracy theory that the shooting had never happened.
By Monday, the bots had new targets: the Daytona 500 auto race in Daytona Beach, Fla., and news about William Holleeder, a man facing trial in the Netherlands for his suspected role in six gangland killings. It is unclear why.
