Both...You’d never search one and not the other involved.
If they suspected I killed you, they’d search both of our places of residence. Or at least they should. That would include their vehicles, work places etc.
Another example would be the victim documenting or making notes on their laptop about being previously threatened by the shooter. That information would be extremely important to determine motive etc.
Huh? Rape victims have a search warrant on their property looking for evidence against them? That doesn’t happen often.