The Maine Attorney General’s Office has filed criminal charges against a 19-year-old woman who allegedly signed and voted a former roommate’s ballot as her own, a type of case that state officials described as extremely rare.

Local election officials in Orono discovered the potential violation before the ballot was processed. A spokesman for the AG’s office said it appears that election tampering was not the motive.

“It appears that the motive behind the crime was a personal dispute between former roommates, rather than an effort to influence the outcome of the election,” Marc Malon wrote in an email.

The complaint says Alyssa Dau of Orono is charged with two felonies: voting in the name of another and forging the name of another on an absentee ballot return envelope. Those charges, which are class-C felonies, are punishable by up to five years incarceration and a $5,000 fine. Dau allegedly voted using a ballot issued for Evangelia Suleiman.

Both the woman charged and the victim are students at the University of Maine.

Suleiman began posting on social media after her former roommate was charged Tuesday. Suleiman, who posts extensively about politics, wrote in support of former Vice President Joe Biden, while Dau appeared to be a supporter of President Trump and posted a “Women for Trump” sign on her door in the apartment they shared.

“I’m a biden supporter, and because she put up trump related décor, I believe she is a trump supporter,” Suleiman wrote Tuesday evening, after the story about the stolen vote began pinging across the country. “I KNOW voter fraud is not a really big thing and it’s rare. I understand that it’s often used as a right wing fear tactic. It still happened.”

She added in another post: “The irony is she’s a trump supporter and they’re the ones who complain about voter fraud the most,” Suleiman wrote.

In an interview conducted via text message, Suleiman said they did not get along with Dau and the two argued over lots of issues, from garbage at the apartment to politics. Suleiman moved out near the end of September, but had already requested an absentee ballot.

After the move, Suleiman said, they called the postal service to try to have the ballot sent to the new, correct address, but it had already been delivered. Suleiman then made plans to vote in person after the town clerk advised that it was permissible in such cases.

A day after Suleiman cast a ballot in person, the clerk called back.

“A second ballot had been turned in and the signature didn’t match,” Suleiman said. The return address also used a nickname, “Evan,” instead of Suleiman’s full first name, and the handwriting was someone else’s.

“Then I kind of put two and two together and realized Alyssa had stolen it and I told them that’s what I suspected,” Suleiman said. “They immediately launched an investigation.”

The AG’s Office released a photocopy of the signed envelope for the absentee ballot. A stamp indicates the clerk’s office received the ballot Oct. 15. Handwritten notes on the ballot suggest that someone from the clerk’s office spoke to Suleiman the next day.

“Ballot believed to be voted by someone other than voter,” one note reads.

The exhibit did not contain a copy of the ballot itself, and Suleiman does not know which candidates were selected on the contested ballot.

A detective later told Suleiman that once confronted, Dau confessed.

Dau did not respond to multiple requests for an interview Tuesday evening.

Voter fraud is extremely rare in the United States, and a spokesman for the AG’s office said officials can remember no cases like this one.

“Our attorneys are aware of just one case in the past twenty years where we have charged (and convicted) a person for voting another person’s ballot,” Marc Malon said in an email. “In that case it was a family member filling out the ballot of another family member. This was the only situation our folks were aware of involving non-related individuals.

“They also estimated that there have been fewer than 5 or 6 cases in the past decade or so of attempted dual-voting, but they need to check their records at the office to get the number right. Suffice it to say it is extremely rare, and the type of case we filed today is even more rare.”

The attorney general said the state will vigorously prosecute any vote fraud.

“We will work closely with the Secretary of State’s Office to ensure the integrity of elections,” Attorney General Aaron Frey said. “It is a serious crime in Maine to cast or attempt to cast an illegal vote, either absentee or in person. My office will vigorously investigate and prosecute any allegations of election fraud.”

Despite the rare cases of fraud, President Trump has repeatedly made false and misleading claims about its prevalence and continues to say in tweets and during campaign rallies that universal vote-by-mail, early voting and other non-traditional ways to cast ballots are inherently unsafe.

Studies of voter fraud, including The Brennan Center for Justice’s compilation of research on individual elections where fraud had been alleged, found that in elections that were checked meticulously for voter fraud, voter impersonation occurs in about 0.0003 percent of ballots cast, at most.