Hours after Philando Castile was shot and killed by a St. Anthony police officer in 2016, during another heated presidential election, a mysterious Facebook page began to run ads promoting a protest called "Justice for Philando Castile."

Black Lives Matter activists in Minneapolis knew nothing about it. Soon they learned that the website associated with the Facebook page "Don't Shoot" was registered to a seemingly false name and address.

A year later, U.S. intelligence analysts released a report saying the Russian government had sought to interfere in the 2016 presidential election using social media. Subsequent law enforcement and media investigations uncovered a sham organization called "Blacktivist" — a troll operation run from St. Petersburg, Russia, led by a Kremlin-linked group known as the Internet Research Agency (IRA).

Four years later, fears that foreign actors might be trying to exploit social divisions are again preoccupying election officials in Minnesota, a known target of Russian meddling in 2016.

A dramatic rise in mail-in voting, a pandemic and inflamed tensions around racism and policing — issues playing out in real time in Minnesota — are ripe for exploitation by adversaries seeking to interfere in the November election, lawmakers and experts are warning.

In some ways, the run-up to the 2020 election is mirroring that of 2016: a bitter presidential election stoking partisan divides; the death of a Black man in Minnesota police custody fueling nationwide unrest; and a torrent of misinformation and disinformation online trying to take advantage of it all.

But federal intelligence officials, analysts and state election administrators expect disinformation to play an even greater role in this year's election than in 2016, when Russia waged a vast campaign to meddle in the election. Russian hackers tried to penetrate all 50 states' election systems that year. They are now instead expected to focus more on sowing division and discord through intentionally false posts online.

"The ground is more ripe now, everything has been heightened and we are more polarized," said Brett Schafer, media and digital disinformation fellow for the Alliance for Securing Democracy. "We are more divided, which of course makes us more vulnerable. I think we are in a worse space than we were in 2016."

U.S. Sen. Amy Klobuchar, D-Minn., called disinformation campaigns "much more insidious and much easier to do" than trying to hack into voting systems.

"Where they just kind of go on either side: They go on either side of pipeline battles, they go on either side of gun battles," Klobuchar said in an interview. "They do it so that people get mad at each other and that they do really blatant things discouraging people from voting in different ways."

This month, Klobuchar was joined by 16 other senators, including U.S. Sen. Tina Smith, D-Minn., in a letter to social media and tech executives urging more action to stop voting-related misinformation and disinformation. The senators warned that disinformation still thrives online, noting a 2019 report that politically relevant disinformation reached more than 158 million Americans. Researchers have said that despite better efforts to curb the spread of disinformation on online platforms, more is reaching users ahead of this election than before the 2016 vote.

Four years ago, the aim was to spark both real-world and online clashes by posting content on opposite sides of the racial divide. A Senate Intelligence Committee report on Russia's interference in the 2016 election concluded that "no single group of Americans was targeted by IRA information operatives more than African-Americans."

This year Facebook, In­stagram and Twitter have already removed numerous fake accounts linked to Russia's Internet Research Agency that were promoting stories about race.

Minnesota Secretary of State Steve Simon still receives classified federal intelligence briefings and is expecting at least one more before Election Day.

"Spreading knowingly false information about election procedures and policies, pitting groups against one another on social media and other platforms," Simon said. "That, we know, is a threat vector that involves more than just one foreign government."

Simon's office is also soon pushing out a public awareness campaign about voting options for the general election. Early voting began in the state on Sept. 18.

Minnesota is playing a more central role in the 2020 presidential race than it did in 2016, as President Donald Trump has vowed to flip the state for the first time in nearly 50 years. Even then, however, a new volume of the Senate Intelligence Committee Report on Russian activities described how former Trump campaign manager Paul Manafort shared Minnesota polling data and discussed the state with a Russian intelligence officer, describing the state as one of four key battlegrounds.

Panayiota Kendeou, a University of Minnesota educational psychology professor who studies misinformation, said the way Minnesotans consume and share information will determine a lot about how the election plays out in the state.

"This is going to sound a little bit extreme, but if we could get everyone off social media until the election that would ideal," Kendeou said. "The information ecosystem right now is lacking curation and gatekeepers."

FBI Director Christopher Wray has told Congress that Russia is still working to influence the election and wants to "denigrate" Democratic challenger Joe Biden, much as it did Hillary Clinton in 2016, because the Kremlin sees him as "anti-Russian." Last week, Wray told a Senate committee that the election cycle's overlap with the COVID-19 pandemic "provides ample opportunity for hostile foreign actors" to carry out disinformation campaigns to "mislead, sow discord, and, ultimately, undermine confidence in our democratic institutions and values."

Schafer's top concern is that foreign or domestic actors are seeding the ground to use disinformation to question the legitimacy of the presidential election, particularly if it is close or if results are not immediately known.

In a Sept. 3 briefing to federal and state law enforcement, the Department of Homeland Security warned that Russia would likely continue to amplify criticism of vote-by-mail and other changes to voting processes amid the pandemic to try to undermine public trust — capitalizing on a political debate that has already seen multiple legal challenges in Minnesota.

"This public discussion represents a target for foreign malign influence operations that seeks to undermine faith in the electoral process by spreading disinformation about the accuracy of voter data for expanded vote-by-mail," the bulletin read.

Simon is counting on increased awareness of how to vote early and why this year's election may not look the same as any other. Experts such as Schafer believe social media companies are better positioned to spot and remove fake accounts before, rather than after, the election.

But Emily Vraga, a health communication professor at the University of Minnesota's Hubbard School of Journalism and Mass Communication, is urging Minnesotans to be more vigilant online and take extra time verifying sources of information, particularly content that provokes "extreme emotion."

"I think the reason we need to be especially concerned and to remind ourselves to do the work is that we are in the homestretch [before the election] and this has been an incredibly difficult year on so many fronts," Vraga said. "We are all tired and the work I'm proposing is actual work — to take the time to double-check — and work is exhausting."

Stephen Montemayor • 612-673-1755

Twitter: @smontemayor