Donald Trump campaign manager Corey Lewandowski can be seen on C-SPAN footage grabbing the arm of Breitbart reporter Michelle Fields.

Breitbart News reporter Michelle Fields is demanding the apology she thought she would receive two days ago, as new video appears to support her charge that Donald Trump campaign manager Corey Lewandowski forcefully grabbed her by the arm — leaving bruises — after a press conference on Tuesday night.

In an interview with Fox News Channel's Megyn Kelly, Fields said the campaign privately promised an apology following the incident, before doing an about-face and publicly denying that anything had happened, according to a transcript provided ahead of Friday's edition of "The Kelly File." Fields has filed a criminal complaint against Lewandowski.

I didn’t want to do it. After this had happened, I called my editor, [Matthew Boyle]. I told him what had happened. I didn’t want to file a police report. I didn’t want to make a big deal out of it because, you know, I didn’t want to be all over the press, and I certainly was worried about my job. What would happen if I went to the police?

I told my editor, and he called Corey and he spoke to him, and Corey said that he did it. He did not deny it. He said that he didn’t realize that I was a Breitbart reporter. Hope Hicks, who is Donald Trump’s spokeswoman, asked for my cell phone number, and I was told that I was going to get an apology. So I waited on that. I didn’t want to make a big deal — this wasn’t going to be a big deal. They were going to apologize; we were going to move on.

I never got that apology. Instead, yesterday, they released a statement calling me a liar. They have basically done a character assassination on me. They are linking to blogs with conspiracies about me. They’re not telling the truth. There’s videos, there’s pictures, there’s an eyewitness of a Washington Post reporter who is very credible. They seem to not understand that. Their statements continue to say there’s no eyewitnesses, there’s no pictures, there’s no videos. They continue to lie.

Washington Post reporter Ben Terris witnessed the arm grab and described it in a story on Thursday. Also Thursday, Fields wrote a first-person account of the episode and posted a photograph of her bruises on Twitter.

But on Friday morning, Breitbart published a story that challenged the assertions by Fields and Terris that Lewandowski was the offender. Based on an elaborate reconstruction of the media scrum that followed Tuesday's press conference, the report concluded that another member of Trump's entourage was probably the guilty party.

Terris didn't waver on his account: "I saw what I saw," he told the Erik Wemple Blog.

Later in the morning, C-SPAN digital and social media specialist Jeremy Art posted footage of the moment when Lewandowski appeared to grab Fields's arm.

Daily Beast senior editor Andrew Kirell slowed the video down to make the grab easier to see.

On Friday afternoon, Breitbart spokesman Kurt Bardella announced his resignation, saying he couldn't represent a client he didn't believe in.

“My own personal observation is that there is a cycle of behavior that is escalating, and it’s happening exclusively at Donald Trump events,” Bardella said in a statement. “It is wrong, disgusting and indicative of an ugliness that is contaminating the public and political discourse in our country.”