While U.S. Rep. George Santos, R-New York, is hardly the first politician to be indicted while in office, the 13-count federal indictment unsealed this week nevertheless stood out as unusual to campaign finance and white-collar defense experts.

"Typically, when you have a sitting officeholder indicted for campaign finance crimes, they usually revolve around things like the misuse of campaign funds [or] soliciting donations outside the legal limits," said former Federal Election Commission senior counsel Daniel Weiner.

But Weiner, who is now senior director of Elections & Government Program at the Brennan Center for Justice, said Santos' indictment is different.

"What's extraordinary about the Santos case is that at least for now, we're not talking about that," he said. "We're talking about a much more brazen fraudulent scheme of the type that isn't unique to politics. But it's the first example that I can remember recently where a sitting officeholder has been indicted for essentially trying to bilk their donors through what amounts to a somewhat complex scam. And that's somewhat new territory."

Santos, who represents northern Nassau County and the northeastern corner of Queens, pleaded not guilty Wednesday to wire fraud, money laundering, theft of public funds and making false statements to the U.S. House of Representatives.

He has been accused of engaging in multiple fraud schemes that appear mostly unrelated, involving everything from an allegedly fraudulent application for unemployment benefits at the beginning of the COVID-19 pandemic to a scheme to launder campaign contributions to his 2022 congressional campaign.

Michael Weinstein, a former U.S. Department of Justice trial attorney and current chair of the White Collar Defense & Investigations Department at Cole Schotz, said Santos' need to mount multiple defenses to the various schemes will present challenges for his defense team.

Santos told reporters Wednesday that he has "plenty of evidence" he plans to share with the government in the course of his defense.

"I'm going to fight my battle," he said. "I'm going to deliver. I'm going to fight the witch hunt. I'm going to take care of clearing my name and I look forward to doing that."

Weinstein said Santos' "bravado" is fairly typical for a politician facing indictment.

"It's not unexpected that that's what he'd say," Weinstein said. "But in the cold dark reality of federal criminal law, that's going to fall by the wayside pretty quickly once the evidence comes to light and once he realizes he's in a deep hole, potentially without a shovel."

Joe Murray, Santos' attorney, did not respond to requests for comment.

Weiner said Santos' indictment sheds light on what steps the DOJ is willing to take to confront "scammy political behavior," which he said has increased in recent years.

"There's been an open question about to what degree the Department of Justice would respond, not just by bringing these kinds of narrow campaign finance prosecutions but by really employing the much broader set of federal anti-fraud laws, and this is an indication that at least in very extreme cases, they are willing to prosecute people under those statutes," Weiner said.

Weiner said he would not be surprised to see an amended indictment charging Santos with some of the other allegations that have been reported in the press, including "more conventional campaign finance violations."

"Now, those are very hard to prove as a criminal matter, because you have to show not only that the person committed the act intentionally but that they knew what they were doing was illegal," Weiner said. "So it could be that they're holding back on those or it could be that they're still investigating them."

The New York Times first published reports on major discrepancies in Santos' resume and reported accomplishments in late 2022, weeks after Santos was elected to Congress.