Election security updates: FBI says bomb threats appear to originate from Russia

At a press conference, a Maricopa County official debunked misinformation circulating on X about voting centers in the county being shut down due to issues with the printers.

"There have been no vote centers that have been shut down," said Maricopa County Supervisor Bill Gates.

Earlier today, Tyler Bowyer, an executive with Turning Point USA who was charged in the Arizona 2020 fake elector case, posted on X that the right-wing group was sending buses to move people to functioning voting centers in Maricopa County.

"We have reports of multiple vote centers with ink issues in Maricopa County," Bowyer posted.

Gates said the printers are being serviced as usual. "We are out there going ahead and servicing the printers as we normally would," the Maricopa County official said in response to Bowyer's tweets.

The Maricopa County supervisor said that as of Monday, more than 1.5 million voters in the county had returned early ballots. About 70- 75% of those votes will be reported in the first batch of results at 8 p.m., he said.

Gates also said that if voters get in line at 7 p.m., they will have an opportunity to vote no matter how long lines are.

"Stay in line and go ahead and vote," he said.

-ABC News' Laura Romero

The FBI arrested a man in Michigan who allegedly posted threats online saying he would carry out a mass shooting on conservative Christians in the event former President Donald Trump wins the 2024 election, according to newly unsealed charging documents.

Isaac Sissel was taken into custody yesterday in Canton, Michigan, just two days after law enforcement reviewed his online posting.

The criminal complaint says Reddit had previously reported Sissel to the FBI in late September over various accounts he had with threatening usernames, including, "ShootUpTrulyRally" "WillShootTrumpSoon," "PlannigToShootTrump" and "PlanningToKillTrump."

Law enforcement contacted Sissel yesterday at a Travelodge hotel in Canton and found no weapons in a consented search of his room, though the affidavit notes "this was not surprising given that SISSEL stated [in his online post] that he 'hid the gun.'"

Sissel further told agents Trump "was a threat...that should have been assassinated, and that everything would be better if Trump was dead," the affidavit says. While he said he wouldn't personally assassinate Trump, he told agents he believed there would be violence during the election "and wouldn't rule out joining Antifa to protest."

Sissel, according to the affidavit, is a transient who has more recently lived around the University of Michigan campus and has several open warrants for his arrest on charges of stalking, harassment and harassing communications.

The arrest underscores the FBI's aggressive response to counter a wave of violent threats surrounding the presidential election, particularly in the wake of the two assassination attempts targeting Trump. In the affidavit, the FBI specifically noted Trump's plans to appear in Michigan for a rally late Monday.

According to his court docket, Sissel has not been arraigned and has not entered a plea to the charge as of Tuesday afternoon. He has not yet been assigned an attorney.

-ABC News' Alexander Mallin

Philadelphia District Attorney Larry Krasner said that while he believes behavior at the polls has been "a little bit more aggressive," no arrests have been made in the city.

Matt Stiegler, senior adviser to the DA, said the office is "monitoring" reports of voters recording poll workers. Stiegler said the DA has gathered these from media reports, but he wouldn't say whether poll workers have reported cases of being recorded.

"Hidden camera recording of election workers and voters and poll workers, that's not normal," Stiegler said. "If that's occurring, then that's a significant escalation of what's happened in the past."

Krasner said his office has seen no indications of voter fraud. Any irregularities, however, would likely not be reported until later in the evening, he noted.

"We do not have reports of anything that looks like voter fraud...We do not expect to have it, but if it's there, we want to know about it. We don't want to hear a bunch of crazy fiction later about how things happen," he said.

"If we start to hear about it at nine o'clock after the polls are closed, you should be rightly suspicious of what you are hearing."

DA Krasner repeated his warning yesterday that consequences would be in order for lawbreakers.

"There are handcuffs, there are cells, there are courtrooms, and there are Philadelphia jurors who are definitely going to want to know why it is a person tried to erase their votes, block their votes, bully their votes, or take away their votes," he said. "We're voting in Philly. We're voting our conscience. We're voting for whoever is our favorite candidate."

-ABC News' Chris Boccia

A Pennsylvania judge ordered the voting hours to be extended for two hours in Cambria County, Pennsylvania, after the location experienced technical issues on Tuesday.

The polls will now close at 10 p.m., per the order, and any ballots cast after 8 p.m. will be cast by provisional ballots.

Lara Trump, the former president's daughter in law and current co-chair of the RNC, praised the ruling as "good news."

-ABC News’ Olivia Rubin