shooting

Killing robbers

Q:

1- As in this time robbery is common in our society. Some time robbers snatch costly things on gun point. I want to ask what is Islamic teaching about protecting our goods. Does Islam teaches us to resist in this situation from snatching or protecting his/her life is more important? As if one resists before robbers they may harm that person or even kill him.

2- If during robbery one kills robbers is this allowed or not? Will this person be treated a killer in the sight of Islam or during defence this is allowed?