That is from the news link...sure looks like a "Mugshot' so I assume that is Chris Williams the guy with the gun. Looks to be between 30's and mid 40's and on the larger side of average. Doubt we will ever see pictures of the accuser unless this goes to trial.
I am surprised the cops in this case did not charge the fellow who started all of this with disturbing the peace, Honestly you have go to be pretty off balanced to go and confront someone over a bumper sticker.