The Jupiter, Fla., Police Department released a video that appears to show Donald Trump’s campaign manager, Corey Lewandowski, grabbing Breitbart reporter Michelle Fields. Lewandowski was charged with battery by police on March 29. (Jupiter Police Department)

Republican presidential front-runner Donald Trump defended his campaign manager as a “very decent man” Tuesday, hours after the staffer was charged with battery in Florida for allegedly grabbing a reporter and yanking her away from Trump.

Corey Lewandowski, 42, faces one misdemeanor count of battery as a result of the March 8 incident. He voluntarily went to police headquarters in Jupiter, Fla., and signed paperwork ordering him to appear in court May 4.

The police also released a video of the primary-night news conference, taken from the security cameras at Trump’s own golf club. It directly contradicted what Trump and Lewandowski said about the incident in the past.

They had asserted that Lewandowski never touched the reporter, Michelle Fields.

In the video, he does — grabbing her hard enough to pull her backward.

In the past, campaign staffers have been fired for far less. But Trump did not dismiss Lewandowski on Tuesday, and neither apologized. “I don’t discard people. I stay with people,” Trump said.

It was an extreme example of Trump’s approach to campaigning, one apparently based on the idea that the only mistake in politics is to apologize.

In this case, that approach seems to have backfired: By refusing to admit any fault, Trump and Lewandowski appeared to have transformed the grab of an arm into a weeks-long controversy, a criminal charge and a TV-ready illustration of how they have disregarded the truth.

As the day went on, Trump offered increasingly strident defenses of Lewandowski. All ran counter to his earlier statements that the contact never occurred. Trump conceded that Lewandowski had touched Fields but implied that it was Fields’s fault for “grabbing” at the candidate — although the photo Trump posted didn’t show a grab but rather the reporter brushing the candidate with the back of her hand.

Then Trump wondered whether he could file charges against the reporter.

And then, at the end of the day, Trump was back to implying that Fields had lied about the incident — if the grab was as bad as she said, he said, why hadn’t she screamed?

“How do you know those bruises weren’t there before? I’m not a lawyer,” Trump told reporters on his plane, referring to finger-shaped bruises that Fields showed to the police. “Wouldn’t you think she would have yelled out a scream or something if she has bruises on her arm?”

Republican presidential candidate Donald Trump's comments on his campaign manager, Corey Lewandowski grabbing Breitbart reporter Michelle Fields before and after police released video footage. (TWP)

In an interview with Sean Hannity on Fox News on Tuesday, Trump said that Lewandowski was merely protecting him against a potential, unidentified threat.

“She grabbed me and she had something in her hand. I don’t know what it was,” he told Hannity. “It looked like it could have been a pen. But you know, from the standpoint of where we are, who knows what it is.”

Fields did not reply to a request for comment Tuesday. She resigned from Breitbart on March 14 after the news organization raised questions about whether Lewandowski had actually grabbed her.

On Twitter, she responded Tuesday to one of Trump’s messages by saying, “Seriously, just stop lying.”

The charge against Lewandowski is explained in an affidavit written by Marc Bujnowski, a detective with the Jupiter Police Department.

Beyond the security-camera footage, the affidavit cited interviews with Fields and said that Bujnowski had seen bruises on Fields’s forearm. They “appeared to be several finger marks, consistent with a grabbing type injury,” he wrote. Bujnowski also interviewed Washington Post reporter Ben Terris, who saw the incident and described it in print. The affidavit does not indicate whether Lewandowski was interviewed by police.

“Lewandowski . . . grabbed Fields’ left arm with his right hand, causing her to turn and step back,” Bujnowski wrote in the affidavit. It continued: “Probable cause exists to charge Corey Lewandowski . . . with (1) count of Simple Battery.”

Under Florida law, battery is committed when a person “actually and intentionally touches or strikes another person against the will of the other.”

A spokesman for the Jupiter Police Department said Lewandowski was not handcuffed and did not have a mug shot taken. After being informed that he would be charged, police said, Lewandowski voluntarily went to police headquarters.

“He came in by himself, without us picking him up, and signed his notice to appear,” said Officer Joseph Beinlich, a Jupiter police spokesman.

In a statement defending Lewandowski, Trump’s campaign said he will be represented by Florida lawyers Scott Richardson and Kendall Coffey. A well-known legal figure in South Florida, Coffey was the U.S. attorney there in the 1990s, but he resigned after allegations that he bit an exotic dancer on the arm at a nightclub, according to press reports.

“Mr. Lewandowski is absolutely innocent of this charge. He will enter a plea of not guilty and looks forward to his day in court,” Trump campaign spokeswoman Hope Hicks said in the statement. “He is completely confident that he will be exonerated.”

Trump leads in the race for Republican delegates, although it is still possible that he will fall short of the 1,237 needed to win the party’s nomination without a convention fight. The next GOP primary will be next week in Wisconsin, where Trump and Sen. Ted Cruz (Tex.) are in a close race.

In the meantime, however, Trump’s hard-edged — and increasingly personal — approach to politics seems to be alienating the broader electorate he would need in a general election. Sixty-seven percent of Americans said they had an unfavorable impression of Trump in a Washington Post-ABC News poll this month, surpassing the highest negative marks for any presidential candidate in more than three decades of Post-ABC polling.

On Tuesday, both of Trump’s remaining rivals for the GOP nomination criticized his handling of the incident.

“It’s a very sad development,” Cruz told reporters outside a restaurant in Milwaukee. “This is the consequence of the culture of the Trump campaign. The abusive culture. When you have a campaign that is built on personal insults, on attacks, and now physical violence. That has no place in a political campaign.” Ohio Gov. John Kasich said he would have fired Lewandowski if such an incident had happened in his campaign, according to press reports.

Democratic front-runner Hillary Clinton, also campaigning in Wisconsin, said Trump is ultimately responsible for what happens at his events and accused him of “inciting violent behavior, aggressive behavior, that I think is very dangerous.” She praised Fields for pursuing charges in the case but stopped short of calling for Lewandowski to be fired.

In this case, it appears that Trump and Lewandowski had helped bring on this criminal investigation by publicly denying that Fields was telling the truth.

In fact, in the days after the incident, Trump’s campaign said it believed that Fields was grabbed by another man in Trump’s entourage — possibly a security official.

Asked about it after a Republican debate, Trump told CNN that he believed Fields had fabricated the story.

“This was, in my opinion, made up,” Trump told CNN then. “Everybody said nothing happened. Perhaps she made the story up. I think that’s what happened.”

Fields said she was spurred to file a criminal complaint to show that she had not lied.

“I didn’t want to file a criminal complaint. I never wanted to do that,” she told Megyn Kelly of Fox News on March 14. “I needed a report to show people that this happened.”

Even after the complaint was filed, Lewandowski continued to say he had never touched Fields. In a previously unpublished interview with The Washington Post — conducted last Wednesday at Trump’s Mar-a-Lago estate in Palm Beach — Lewandowski continued to assert that he never made contact with Fields.

He said it was wrong to think that he had cleared Fields away from Trump’s path because he thought she would ask him an uncomfortable question.

“Just the premise that Breitbart is going to ask Mr. Trump a question that he can’t handle, and I’m so concerned what this question might be — on its face, that is just an egregious notion,” Lewandowski said.

A reporter pointed out that Terris, the Post reporter, saw the incident unfold.

“I don’t know. I don’t know what Ben did or didn’t see. I have no idea, but I’m not calling into question anything other than the fact that I don’t know him. He and I have never met,” Lewandowski said. “I don’t know Ben, and I don’t know [Fields], and I’ve never met her.”

But, even then, the police case was heading toward its conclusion.

Law enforcement experts said that once Fields filed her complaint, Jupiter police had no choice: They were bound to investigate it. And, once they investigated it, they found what appeared to be straightforward evidence: an overhead camera that showed Fields being grabbed.

And once police found “probable cause” that a crime was committed — a legal standard that means it is more likely that the crime was committed than not — they could file charges.

“She made a formal complaint, so that is why they handled it the way that they did,” said Barry Maxwell, a defense attorney and former prosecutor in Florida.

In theory, Lewandowski could face up to a year in county jail if convicted. But attorneys and legal experts said that is highly unlikely. Lewandowski could fight the charge, perhaps by arguing that he saw Fields as a threat to Trump’s safety. And, even in the case of a conviction, experts said first-time offenders convicted of battery are often sent to anger-management courses, not jail.

Callum Borchers, Jose A. DelReal, Karen Tumulty, Sean Sullivan and Abby Phillip contributed to this report.