GEOFF BENNETT: Welcome to the "News Hour."

Federal agents searched the Washington, D.C., home of Minnesota Democratic Congresswoman Ilhan Omar early this morning.

The reason for the search has not been made public.

Agents with Homeland Security Investigations, the investigative arm of ICE, were seen carrying boxes from the home into an unmarked car.

Omar accused the Trump administration of political intimidation, writing on social media -- quote -- "Make no mistake, this is an attempt to target political enemies and weaponize federal law enforcement."

For more, we're joined now by Devlin Barrett, Justice Department reporter for The New York Times and author of the book "The Department of Revenge: How Trump Took Control of American Justice."

Devlin, always great to have you with us.

So the DOJ says this search is part of an ongoing criminal investigation.

What have you learned about what prompted it and what investigators are looking for?

DEVLIN BARRETT, The New York Times: So, Geoff, the Trump administration has been signaling just such a move for months now.

If you go back to the spring, J.D.

Vance, the vice president, said that Ilhan Omar -- quote - - "definitely committed immigration fraud."

And DHS officials have since said they're investigating.

So this move isn't much of a surprise, but I think it does speak to the way that law enforcement actions keep happening at the at the impetus and prodding of the White House.

And what's at issue here, according to our sources, is all the paperwork in the congresswoman's family that led them to becoming U.S.

citizens.

That's paperwork that her father filled out, paperwork that was done later.

And what they're investigating is false statements on immigration documents potentially and various types of fraud and conspiracy.

GEOFF BENNETT: A federal judge had to approve this search warrant, so what does that suggest about the evidence investigators presented?

Would it have been the sort of documents that you're talking about?

DEVLIN BARRETT: Right.

So they have to show probable cause to believe that evidence of this crime or possible crimes existed at her house.

And probable cause is not the same thing as the amount of evidence it takes a jury to convict.

We are told by sources that prosecutors first applied for this search warrant more than a week ago.

And that led to a back-and-forth with a federal judge over whether they had shown enough of a legal argument for why they needed to do this and whether they had considered the issues related to the constitutional protections that are specific to a lawmaker.

GEOFF BENNETT: And, of course, we're talking about federal agents searching the home of a sitting member of Congress.

How extraordinary is that?

What safeguards are supposed to govern an investigation this sensitive?

DEVLIN BARRETT: Well, the federal government does investigate lawmakers all the time.

That's not particularly unusual.

What's so unusual here is that they're doing it 22 days before an election, because the Justice Department has for many years followed something called a 60-day rule, which is basically meant to go quiet, make the Justice Department go quiet about things exactly like searches of lawmakers' homes and businesses, because they don't want to be seen as trying to influence the election.

Here, what you see is a very publicly observable, overt act of investigation that past administrations would have done everything they could to try to avoid doing just before an election.

GEOFF BENNETT: What would legal experts look for to distinguish a legitimate criminal investigation from one driven by political motivations?

DEVLIN BARRETT: Well, it's things like, what is the basis of the evidence that leads you to probable cause?

Obviously, a judge has determined that there is some probable cause here.

And -- but, at the same time, we also know that there was the judge didn't immediately accept that application, that there was some back-and-forth before they got to this point.

I think one of the ways in which the Trump administration sort of creates its own headaches and its own problems when it comes to criminal investigations is, remember how this process began.

It began with the vice president of the United States publicly declaring her to be guilty.

And there's obviously a long history of the president himself, Donald Trump, accusing Ilhan Omar of various things.

So the challenge that will -- that the government will have to overcome if it proceeds to try to charge her is overcoming questions or skepticism about, what was the motivation behind this investigation?

GEOFF BENNETT: And when you say if the government proceeds, what would come next in this investigation?

DEVLIN BARRETT: Well, if they decide they have enough evidence that they can get an indictment, then they would present their evidence to a grand jury.

What's going to happen now is, after - - now that there's been a search and we have seen agents taking away boxes of evidence, they're going to have to sort through everything they have taken.

And there may be some fights, legal fights, to come over what of that evidence that is seized is properly part of the investigation.

And so we don't know if there's going to be a legal fight over that.

I wouldn't be surprised if there is.

But the next prosecutorial step, assuming that they know what evidence they have and they believe it would survive a vote in a grand jury, would be to present the evidence to a grand jury.

GEOFF BENNETT: Devlin Barrett of The New York Times and the author of the book "The Department of Revenge: How Trump Took Control of American Justice."

Devlin, always a pleasure to speak with you.

Thanks.

DEVLIN BARRETT: Thanks, Geoff.