This is On Trial, a special series from Dateline True Crime Weekly, bringing you daily coverage from the Sean Combs racketeering trial. He has pleaded not guilty to all the charges against him. I'm Andrea Canning, and it's Wednesday, June 4th. Just a heads up, in this episode, we're going to be talking about some graphic details and harrowing subject matter.

Today, federal prosecutors called the eighth witness they've had to subpoena to testify against Sean Combs.

Some of his personal assistants, a hotel security guard, and now Brianna Bongolan.

She had been a close friend of Cassie Ventura's. On the stand,

Brianna told the jury that Combs once told her he was the devil and that he terrified her.

NBC News correspondent Chloe Malas is in downtown Manhattan to get us up to speed. Hey, Chloe. Hey, Andrea.

Okay, so tell us about Brianna and who she is to Sean Combs. So she's a fashion

and graphic designer and she partied with Diddy. They worked together. And there has been a lot of

anticipation about her testifying. Brianna testified under an immunity agreement. Chloe,

what do you know about this agreement?

Well, she testified about doing illegal drugs with Diddy and Cassie and about getting those drugs and sometimes getting paid back for them by the couple.

So, you know, this is something that we've seen with other witnesses taking the stand granted immunity by the government so that, look, you can say whatever your truth is as long as it's the truth,

and you're not going to be held legally accountable for anything.

Her demeanor was very subdued?

Very, almost breathless. At times, it was almost like a whisper.

I can only imagine just how hard it is for some of these people, especially the ones, you know, who are being subpoenaed to get up there and take the stand.

How does Brianna's testimony help the prosecution's case?

Prosecutors are trying to show that there was this pattern of violence.

They're trying to corroborate Cassie and other victims' allegations of physical and sexual

abuse.

And when it comes to Brianna, she's testifying that she saw Diddy be violent towards Cassie?

And that, you know, also she experienced violence from him.

...