system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter] What would have happened if Mr. Dursley had shot Hagrid at the shack on the rock?

This is mostly a question of Giant physiology. If Mr. Dursley shot Hagrid, would he die?

Hagrid wasn't defending against attack, didn't have his wand ready, and rifles can be very dangerous.

Assume a large caliber round to the chest. The type one would use to kill a bear. Hagrid bursts in, surprises Mr. Dursley and is shot.

Would he die?

Also, afterwards, is it a crime for Muggles to kill wizarding folk? I'd assume it probably is, but it's hard to fault Mr. Dursley for acting in self defense. If a bear-sized man kicked down my door in the middle of the night I'd shoot him too.
gpt
The durability of the giants is partly magical and partly physical. It's also worth noting that Hagrid's moleskin overcoat posesses some magic of its own, among which defensive enchantments may be included. Being shot would not be a particularly pleasant experience for Hagrid, but more likely than not he would survive. 

As for muggle/wizard crimes; this depends very heavily on the circumstances. Usually involved (muggle) parties will have their memories altered to fit a more mundane version of events. The muggles are then left to sort out their own. However, crimes that are very magical in nature are taken to wizard courts, where they are allowed to stand trial with a wizard representative who helps interpret. Those who are found guilty are handed off to the local muggle government, and magically appear in the system for processing.