You can fire a shot into the wall, well above head height. The blast of the gun will cause the crowd to pause & reevaluate how much they want to get through that door. There weren't that many people on the other side of that wall and within seconds of her getting shot, several cops came forward carrying AR-15s.How exactly do you fire a warning shot inside with a mob of people? I’m sorry, you are way out to lunch on this one.
And just for the record, this happened while Trump was still in office and his administration.
A warning shot would have defused the situation and no one had to die.
The investigation and determination of whether it was a legal shooting occurred, when Biden was President.