But I have no more information than anyone else does, I'm making a low-confidence educated guess, and at some point in the near future it's very likely that the professionals whose job it is to investigate serious crimes will have a better idea of what actually happened than anyone posting in this thread.
In a neighborhood with mixed SFHs and condos, it makes little sense to target a condo. Makes even less sense for someone to break in, but to shoot the victim outside, in the foyer.
It's a tough one to find a motive for...