Michelle Fields, who was a reporter for conservative website Breitbart News Network at the time of the incident, said she was grabbed by Lewandowski at a Trump press conference in early March.
Jupiter, Florida police released video showing the incident.
Fields and then Breitbart editor-at-large Ben Shapiro resigned from Breitbart in mid-March following the allegation. Breitbart's senior editor-at-large reportedly asked reporters to not tweet in defense of Fields about the story.
When she resigned, Fields said in a statement,
I do not believe Breitbart News has adequately stood by me during the events of the past week and because of that I believe it is now best for us to part ways.
Lewandowski denied this incident took place.
The Trump campaign manager turned himself in to Jupiter police on Tuesday morning.
In a statement, the Trump campaign maintained Lewandowski "is absolutely innocent of this charge."
Citations: Trump aide charged with misdemeanor battery vs. ex-Breitbart reporter (Palm Beach Post), Reporter And Editor Resign From Breitbart Site Over Alleged Assault At Trump Event (NPR), Michelle Fields, Ben Shapiro Resign From Breitbart (BuzzFeed)