“grabbed his AR-15”
Had he had something like just a 9mm handgun; he likely wouldn't have brought the killer down.
Thank goodness he had some firepower.
Likely most media won't bring this fact up as they have no room for a good story about a AR-15.
I might have grabbed my 7mm mag bolt gun. Loads very fast and a 185 g bullet would have perforated the tactical gear the nut job was wearing.
But two 55 gr fmjs did the job!