Responses
Im sure when the detective interviewed her in the room, the detective told her something else aside from what was shown to us. Maybe the detective told her about a safe place where she could go for emergency or contact her or something when she needs him. Maybe they even planned something but that's a bit far fetched considering she didn't completely believe Inseop could be a killer. I think the detective wouldn't risk revealing the plan to her if they know she's on the fence about Inseop.
ok now I need her to change EVERYTHING her and the brothers names, her number, her profession, everything cuz korea is only so big and this psycho is gonna tweak something serious like she needs to get as far as possible cuz if he finds them its gonna go badly