Unlike Miguel, I am going to take the Buffalo shooter’s manifesto at face value until proven otherwise.
I read it and can tell you that several posts will come from an analysis of it.
But I want to hammer home on this point again:
The shooter states that he targeted locations where CCW was prohibited or low.
He chose a location where if people were armed they would be limited to 10 round magazines and not have access to rifles.
He stated he would be wearing level IIIA armor that could defeat the ammunition carried by the guards at Tops Market.
He thought this attack out to minimize danger to himself, and considering that he was taken alive, it worked.
You need to be prepared to fight someone who is wearing armor and knows you will only have a handgun.
You need to start training to put the first few into the pelvic girdle just in case your assailant is wearing armor.