Killing a thief caught in the act is not a "murder", regardless of whether you think it was justified or not. Maybe, depending on the situation, it was too much in your opinion, but not "murder". I'm not speaking "legally", but ethically. So be careful, because unethical governments (but I repeat myself) take the side of the bad guys and punish the good guys.
If you're a prosecutor who charges such a victim with murder or attempted murder for daring to try to protect his property, you're the bad guy. Maybe even worse than the thieves.
All you're doing is rewarding thieves and making it safer to be thieves. You're encouraging thieves and potential thieves to steal more. This is the opposite of what you ought to be doing. Your worthless "job" is to protect the life, liberty, and property of those who are where they have a right to be, doing what they have a right to do. Not the thieves.
If there are to be "laws" covering such things (there shouldn't be, but there are), they should be similar to the "law" that charges a bank robber with murder if one of his thieving associates dies during the robbery. If a thief is killed while committing theft, the fault is his and his associates'. No one is forcing any of them to be thieves. It's a choice, and choices have consequences. Too bad, so sad.
If I'm on the jury (Ha ha!) for a defender being charged with murder in such a case, he's either walking free, or there will be a hung jury. I will never v*te to convict someone for shooting a thief. Not even if I personally dislike the defender or believe he could have chosen to not defend his property as effectively as he did.






