"Victory press conference was over. Why is she allowed to grab me and shout questions? Can I press charges?" Trump tweeted Tuesday with a photo.
In a second tweet, Trump asked, "Why is this reporter touching me as I leave news conference? What is in her hand??"
Fields said earlier this month that Trump's campaign manager, Corey Lewandowski, grabbed her arm during that same March 8 event in Florida, leaving her with bruises.
Lewandowski has been charged with one count of simple battery for allegedly touching Fields, local police said Tuesday morning.
The police department released video that appears to show Lewandowski reaching out to hold holding the reporter back as Trump passes. Lewandowski reportedly turned himself into police Tuesday morning and has been issued a notice to appear in court May 4.
Trump defended his campaign manager earlier Tuesday, calling him a "very decent man" and saying the video shows "nothing there."
His campaign said in a statement that Lewandowski was issued a formal notice to appear and given a court date and wasn't arrested.
"Mr. Lewandowski is absolutely innocent of this charge. He will enter a plea of not guilty and looks forward to his day in court. He is completely confident that he will be exonerated," Trump spokeswoman Hope Hicks said in the statement.
Updated at 3:36 p.m.