Two days after Pennsylvania’s primary election, Philadelphia elections officials suddenly stopped counting votes.

They had to make sure no one had voted twice — once by mail and once in person — and they couldn’t count a stack of mail ballots in the meantime. Workers turned to scanning the poll books that people sign when they vote in person, and compared those to the list of mail ballots that had been returned, flagging any overlap.

For five long days, the counting stopped.

In the end, the process largely worked: Officials identified 40 people who had returned a mail ballot and then also voted in person. The mail ballots caught in time were excluded to prevent double voting. (Four double votes had already been counted.)

There’s no evidence of fraud, and the problem wasn’t widespread. The June 2 primary was the first election in which any Pennsylvania voter could vote by mail, and coronavirus fears helped fuel an unexpected surge in mail ballot requests — some of which would have been returned too late to count were it not for last-minute deadline extensions granted by Gov. Tom Wolf and some county courts. People were likely trying to ensure their votes were counted and were inadvertently allowed to vote at their polling places.

“They’re not familiar with the process. They haven’t really done it ever before,” said Lisa Deeley, chair of the Philadelphia Board of City Commissioners, which runs elections. “We didn’t have an opportunity to educate the poll worker or the voter as thoroughly as we could have or should have.”

But it nevertheless raises a concern about November, when Pennsylvania is expected to play a critical role in deciding who wins the White House and results could take days to determine. If Philadelphia and other counties want to catch this kind of accidental double voting, they’ll need time to do so.

In the meantime, the world will wait to find out who won.

How double voting happens and how to spot it

Once you request a mail ballot, you’re not supposed to be able to vote at the polls. If you try, you’re supposed to be given a provisional paper ballot, which is set aside and only counted after officials confirm you were allowed to cast it.

Election officials mark your name in the poll books as having requested a mail ballot or voted by mail. When you check in, poll workers should flag you as not being allowed to vote on the machines.

But Philadelphia poll books were printed a week before the deadline to request a mail ballot. Almost 92,000 voters’ mail ballot requests were processed after the books were printed.

Thus, the poll books didn’t identify those voters as having requested or cast mail ballots. City officials printed those names separately, and poll workers were supposed to use that list to ensure nobody double voted.

But even those who are listed in the books or on the separate list can be allowed to vote in person at times, due to poll worker error. That can happen when the workers ignore the mark in poll books signaling that a person had requested or submitted a mail ballot, or fail to consult the printed list.

That’s what happened to Denise Furey, a Republican ward leader, treasurer of the city’s Republican Party, and an official with the state GOP. She sent in her mail ballot but received no confirmation of its being received. So she went to the polls just in case.

“I assumed I was going to be filling out a provisional ballot; I said that to the lady at the front desk when I walked in,” Furey said.

Instead, she said, the poll worker let her vote on the machine. Furey said she was instructed to sign right over the mark that declared her ineligible to vote in that way.

“There needs to be procedures put in place. And really, what it comes down to is the election board workers probably need better training in the future,” she said. “I just think that it was a mistake made on the part of some poll workers, and it was a new system. Things are different, it just unfortunately happened.”

Knowing that poll workers make mistakes, Philadelphia elections officials only counted an early batch of ballots — the ones that had been received before poll books were printed — before putting everything on hold. They found the 40 people who cast two ballots. Of those, 36 were caught in time to prevent being counted twice.

The long wait for results

There’s no evidence of a conspiracy to cheat the system. Four votes out of 347,000 — about 0.001% — were double counted.

A spokesperson for the Pennsylvania Department of State, which oversees elections, said local officials “have a responsibility to engage in reconciliation that ensures the integrity of the election results.” But the law does’t say how.

That means officials will have to decide again in November whether to move quickly to count results that may have some double votes in them — or spend days checking poll books as everyone anxiously waits.

“Obviously, it was frustrating from the perspective of all of the candidates and their teams … in terms of when we received results, and we wish there could be some way to figure this out better in advance of election day,” said Adam Bonin, a Democratic election lawyer in the city. “Harrisburg needs to be a part of that solution.”

Otherwise, to get the most accurate results, we’ll all be waiting again next election. This time, it took more than a week for some races to be called.

“Our main thing is to have an accurate count,” Deeley said. “If you get it done quick and it’s wrong, it doesn’t matter. Accuracy should always be the priority.”