Killing angry people isn't really a improvement on angry people killing others.
Most angry people have reasons for being angry.
They might have been taught that emotions other than anger are inappropriate.
They might have trauma issues, and their Flight/Fight/Freeze/Fawn response is fight.
They might lack the skills to regulate their emotions.
It doesn't justify their anger, but we can be compassionate while keeping them accountable. Their actions are the issue, not their existence.