You don’t have to defend your life; defense of property applies.
1 AM, remember. That’s not murder even by the thinnest-stretched definition.
Montana lawmakers seem to be OK with teenagers “who are simply garage-hopping”, too.
The home owner was in no danger at any time. Could have just as easily held him at gun point and called the police. The use of deadly force is a serious matter, setting up a situation to use it because you’re frustrated by being ripped off, doesn’t seem to me to be the wisest solution to the problem.