Boy, 11, asks girl, 8, to see her puppies. She declines. He shoots and kills her

That is exactly the point.

The brain fart then translates to a bullet going in a safe(r) direction and making noise and minor damage. Without it, there is a risk of it going in an unintended direction and causing real mayhem.

It is not a replacement to the regular securing, an important point. It is an addition.

Stack the probabiliites.