Last I checked 19 isn't a child, and you have remotely diagnosed him with your E-PHD as having mental health problems, without any mention of it on the news.
He was a man, driving a stolen truck, who then tried to flee from police, which led through small town, through red lights while discarding debris along the way.
When cornered, instead of surrendering, he decides to use the truck as a weapon and ram the cops.
How else was this supposed to end?
Were the cops supposed to teleport into the vehicle while it's ramming them, and give him a package of cigarettes and a hug?