So any case in which the shooter knows the intended victim is "domestic violence"? Obviously not. Equally obviously, not all cases where the shooter does not know the intended victim are "random".
I don't know? That was my best guess for why the media reported the shooting as domestic violence. And like I said, your questions are best directed at those reporters. Cause I have no idea why they see it as domestic violence. All I can do is guess.
I personally feel, I don't need to prepare for a madman (which implies women) with a gun. To prevent redundancy I will not repeat my reasons. But I will add, I hope that I will never have to. I hope such incidents cease but that is unrealistic. Therefore, I hope they will never stop being "very rare." I hope as well, there will be no copy cats in relation to this recent horrible incident in California.