Attorney General William Barr doesn't think an election conducted mostly by mail can be done securely.
Barr told NPR's "Morning Edition" on Thursday that he is concerned expanding mail-in voting could result in widespread fraud.
But he said he had no evidence to support his claims that fraud could stem from a mail-based election.
Barr told Steve Inskeep he is concerned with relying heavily on mail service for the presidential election because of missteps that took place in mailing out stimulus checks to Americans.
"I mean, we just mailed out checks under this program. And what is it? I heard something like 20% or something were misdirected," Barr said of the stimulus checks.
He said he thinks the same thing could happen with mail-in ballots.
"I know things can happen like that," he said. "Because I know people move, a very high percentage in the U.S., people move all the time. And I also know that you can easily take things out of mailboxes."
He added, "There's so many occasions for fraud there that cannot be policed. I think it would be very bad. But one of the things I mentioned was the possibility of counterfeiting."
Barr isn't the only one fearful a mail-based election could lead to fraud. It is a position President Donald Trump has taken too.
Many lawmakers are pushing for expanded vote-by-mail measures to be put in place to help stop the spread of the coronavirus.