This are the 10 best average response time cities in the US



If there's a mass shooting, you get something like Christchurh where the shooter just kills dozens of people and police is nowhere to be found
His livestream is at least 10 minutes long, the police is called, but he kills some 50 people, exists the building, and then travels to another building and kills more people there. The police doesn't come in the whole stream (10ish minutes).

But what happened in Whiite Settlement in Texas when a shooting happened?
Shooter shot 2 people before he got shot himself.
If the people in the church weren't armed, another Christchurch would happen because it would take the police 10 minutes to arrive and then engage him, he'd probably even have hostages until then if he  had intention to survive or he would already kill some 50-60 people.