If someone threatens to kill you, you have the right to protect yourself.

If you heard someone breaking into your house, would you like to have a gun to defend yourself?

I believe if you fully consider the situation you would say yes.

The arguments that overall crime rates would drop aren't well supported by data, and there are many other easier ways of reducing the crime rate. But that argument misses the point in the first place--the right to defend yourself is a personal right.