WEST PALM BEACH, Fla. (Reuters) - Republican presidential front-runner Donald Trump’s campaign manager will not be prosecuted in Florida on a misdemeanor battery charge involving a reporter, Palm Beach County State Attorney Dave Aronberg said on Thursday.

Corey Lewandowski, 42, was charged on March 29 by police in Jupiter with intentionally grabbing and bruising the arm of Michelle Fields, then a reporter for the conservative news outlet Breitbart. The incident occurred when Fields tried to question Trump at a campaign event on March 8.

“Mr. Lewandowski has a reasonable hypothesis of innocence. There is insufficient evidence to rebut these defenses,” said Aronberg, a Democrat, noting that Lewandowski had grabbed the reporter’s arm against her will.

Aronberg’s office said it faced a legally higher standard than law enforcement. State prosecutor’s offices must show proof of a crime beyond a reasonable doubt, and whether there is a reasonable chance of conviction.

Law enforcement can bring charges on probable cause, and Aronberg said police had acted appropriately.

He added that politics did not factor into his decision.

Police released a video of the incident showing Fields walking alongside Trump and trying to question him. Lewandowski is seen grabbing her arm and pulling her backward.

Fields had brushed or touched Trump’s arm following a campaign news conference, after which Lewandowski reached out and grabbed her arm, said Aronberg, citing a video recording.

Trump has repeatedly defended Lewandowski, and the campaign released a statement noting that the campaign manager was gratified by the decision of prosecutors.

Lewandowski “appreciates the thoughtful consideration and professionalism by the Palm Beach State Attorney and his staff who carefully reviewed this matter, as well as Mr. Trump’s loyalty and the support of his colleagues and family during this time,” the statement said.

But the decision was a disappointment to Fields, Aronberg said, noting that his office had talked with her on Thursday.

Fields on Wednesday posted on Twitter, “For those asking, office of prosecutor asked 2 weeks ago if I’d be ok with an apology from Corey. I said ya but haven’t heard back about it.”

Aronberg said an apology to the reporter might have avoided the legal proceedings.