The sister may have had legitimate concern about this guy.
He answered the door holding a weapon, which would indicate that he keeps it with him even in the home.
He decided to fire on Police. This is certainly not normal behavior.
Instead of this, we just as well could be reading about another family slaughter.
I wouldn't want this guy in my house carrying a pistol everywhere he goes.
If he would shoot Police, he would certainly shoot me.
But yes. This is a template for armed gun confiscation, which is an ominous harbinger.