GEOFF BENNETT: Welcome to the "NewsHour."

There are new questions tonight about how a National Guardsman entered the military and kept his security clearance before leaking hundreds of classified documents online.

AMNA NAWAZ: Jack Teixeira appeared in a Massachusetts court, and prosecutors accused him of a history of violence and threats long before he allegedly committed one of the most significant intelligence leaks in years.

Nick Schifrin is following the story, joins us here now.

Nick, good to see.

NICK SCHIFRIN: Thanks, Amna.

AMNA NAWAZ: Let's start with the latest today.

What happened in court?

NICK SCHIFRIN: Prosecutors are trying to make sure that Teixeira remains in federal custody.

And to make their case, they painted him as a much more dangerous figure both to the public and to national security than we knew previously.

Take a look at this.

They allege that, in 2018, he was suspended from high school for making remarks about guns, Molotov cocktails and racial threats, an incident that caused Massachusetts to deny him a firearms identification card.

And then they talk about regular violent comments he made online, killing an expletive ton of people to cull the weak-minded, turning a minivan into a -- quote -- "assassination van," and then finally using a rifle in a crowded environment.

They alleged that he used a government computer to research previous shootings and standoffs with federal agents and had a -- quote -- "virtual arsenal" inside his bedroom.

They also describe that he had multiple computers that he threw into a dumpster to destroy to try and cover his tracks.

And that's a picture of all those computers.

And on national security, prosecutors wrote that Teixeira may still have access to a trove of classified information that would be of tremendous value to hostile nation-states that could offer him safe harbor and attempt to facilitate his escape.

Now, it is important to note that there is no evidence that Teixeira leaked these documents to aid one of America's adversaries.

But, clearly, these are extraordinary statements about a 21-year-old airman who only had access to these documents he leaked because he was an I.T.

specialist on a highly secure network.

AMNA NAWAZ: Nick, there are so many concerning details about his background.

The biggest question remains, how did he get, how did he maintain a security clearance?

NICK SCHIFRIN: Yes, first, how did he get it?

So, everyone who has the highest clearance, like Teixeira had, goes through a similar background check.

And DOD does that by interviewing the person's contacts.

And they're supposed to know about state decisions like the one that Massachusetts made denying him that firearms card.

Here's how Press secretary Brigadier General Pat Ryder put it today at the Pentagon.

BRIG.

GEN. PATRICK RYDER, Pentagon Press Secretary: If we're going to award us a security clearance, it's going to be pretty stringent requirements to get that security clearance.

First of all, there is going to be a background check.

You're going to take training and you're going to sign a nondisclosure agreement.

So, at the end of the day, it is not something that you just get.

It's something that you have to essentially earn and then maintain that.

However, if an individual decides to break the law willfully, that's a different story.

NICK SCHIFRIN: So, then there's the question of how he maintained his clearance.

The military has known -- has what's known as continuous vetting, which is supposed to track personnel's financial, criminal, and public records and flag anything that they seem is -- as a risk at all.

And the government computer where he was doing his searchers were also supposed to mark those flags.

And so those are questions that will go into the investigation.

And, tonight, the Air Force confirms that they suspended his unit's commander, as well as another commander at the base where he worked.

AMNA NAWAZ: Nick, these are all alleged crimes right now.

So what do his defense attorneys say about this?

NICK SCHIFRIN: Yes, Teixeira's public defenders are withering in their own criticism of the story that I just laid out.

They say that they have -- quote -- "hyperbolic judgments" about Teixeira.

And they call the part about foreign adversaries -- quote - - "little more than speculation."

And they want him released to his father.

And his father was in court today, and said that he could supervise his son.

In fact, his father said he removed his own guns from his own house, installed some cameras.

He could do that.

The prosecutors -- or the defense attorneys, rather, said that he could be monitored, prevented from going online.

And they pointed out that he is still an active-duty airman, which means he is still under the control of the Air Force, and the Air Force has an obligation to protect him.

And so there is a scenario in which he'd go back into the Air Force -- or, rather, remain in the Air Force, of course, not in his same job, though.

His clearances have been revoked.

AMNA NAWAZ: A lot more details we still need to learn.

Nick Schifrin following it all for us.

Thank you, Nick.

NICK SCHIFRIN: Thank you.