My guess would be assault or assault with a deadly weapon.
In Florida, an assault is intentional threats, words or actions that cause a person to feel afraid of impending violence. (Fla. Stat. §784.011.) Battery is actual offensive physical contact, such as punching another person or hitting someone with an object. (Fla. Stat. §784.03.)
Aggravated assault is an assault with a deadly weapon or with the intent to commit a felony. (Fla. Stat. §784.021.) Assault does not require an intent to injure, only the intent to cause the victim fear of an immediate attack.
But these are state laws. The state is not investigating him, the FBI is. What kind of federal charges can they throw at him? (I suppose the feds could pressure the state to prosecute, but that doesn't appear to be the case).