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Welcome back, everyone.

We are following developments in a scare at election offices across the country just 19 days ahead of the midterms.

An FBI investigation is underway into potentially hazardous packages mailed to several states.

Suspicious letters with white powder for forced evacuations at election offices in Louisiana and Oklahoma.

The Postal Service intercepted other letters sent to other states.

They included Ohio and South Dakota.

Offices linked to Senator Chris Murphy and Alex Padilla were also targeted.

Now, the New York Post obtained this image of one of the envelopes.

It had a return address for an old Democratic Socialist of America office right here in New York City.

A DSA spokesperson told the Post that it did not send the letters.

No injuries or hospitalizations have been reported in any of these incidents.

NewsNation is learning that dozens of packages may have been sent across the country.

Tracy Walder, Steve Moore returning.

Thank you guys for staying with us.

Steve, you led the investigation that resulted in the first ever federal conviction for an anthrax threat.

What should we know? What is the investigation looking like right now?

Well, right now, what you're going to see is a lot more letters, most likely, because if they just hit today or last night, it doesn't mean that every single letter that this person mailed, and they were probably put in post office boxes because they don't want to have an address that they were seen putting an envelope in, and they know there's cameras in post offices.

So These boxes may not have been picked up in time for the sending out across the country.

So there's probably going to be a bunch more of these things in the next day or so.

So, Tracy, we are learning a bit more that Senate staff received a note on Thursday last week warning that law enforcement was working to intercept additional letters before they are delivered.

And of course, it's possible some of these letters have not reached their destinations.

They might still be coming, like Steve mentioned.

What is your biggest worry tonight?

So I think my biggest worry is that they haven't identified the substance that's in them yet, or at least they said they haven't identified the substances in them.

Because as you just mentioned, this has been going on for probably a week.

Welcome back, everyone.

We are following developments in a scare at election offices across the country just 19 days ahead of the midterms.

An FBI investigation is underway into potentially hazardous packages mailed to several states.

Suspicious letters with white powder for forced evacuations at election offices in Louisiana and Oklahoma.

The Postal Service intercepted other letters sent to other states.

They included Ohio and South Dakota.

Offices linked to Senator Chris Murphy and Alex Padilla were also targeted.

Now, the New York Post obtained this image of one of the envelopes.

It had a return address for an old Democratic Socialist of America office right here in New York City.

A DSA spokesperson told the Post that it did not send the letters.

No injuries or hospitalizations have been reported in any of these incidents.

NewsNation is learning that dozens of packages may have been sent across the country.

Tracy Walder, Steve Moore returning.

Thank you guys for staying with us.

Steve, you led the investigation that resulted in the first ever federal conviction for an anthrax threat.

What should we know? What is the investigation looking like right now?

Well, right now, what you're going to see is a lot more letters, most likely, because if they just hit today or last night, it doesn't mean that every single letter that this person mailed, and they were probably put in post office boxes because they don't want to have an address that they were seen putting an envelope in, and they know there's cameras in post offices.

So These boxes may not have been picked up in time for the sending out across the country.

So there's probably going to be a bunch more of these things in the next day or so.

So, Tracy, we are learning a bit more that Senate staff received a note on Thursday last week warning that law enforcement was working to intercept additional letters before they are delivered.

And of course, it's possible some of these letters have not reached their destinations.

They might still be coming, like Steve mentioned.

What is your biggest worry tonight?

So I think my biggest worry is that they haven't identified the substance that's in them yet, or at least they said they haven't identified the substances in them.

Because as you just mentioned, this has been going on for probably a week.