For me, if he was being shot at, then he had the right to shoot back. But he was just being chased. No indication he was gonna get murdered (the armed mob could have just shot him at any moment right?).
That's why for me, proportionally speaking, he went overboard with the self defence.
He shot these people, because sadly, his mind has been brainwashed. Police, guns and violence are his religion. He probably assumes everyone out there has a mind filled with violent intents towards fellow humans just as him.
Seriously, not really. A sensible person just drops his weapon and surrenders before getting to that point. Police were just meters away. He was not gonna get murdered by a mob.
What Kyle did, was the equivalent to the US firing their nuclear arsenal on the world if they were about to lose the war (that they started).