Thomas Rosrocki, of Averill Park, was arrested for Assault in the Third Degree.
Police said that a fight broke out during a pro-Trump rally, and the 59-year-old struck a victim several times in the leg with a walking stick. That victim was walking through the park at the time the fight broke out.
Rosrocki was identified due to witnesses and video. He turned himself into state police and is scheduled to reappear in court on August 23.