It would be ... unless she knew the murderer before the murder took place.

That's what he thinks, anyway, as he picks up on that particular word. It's what he'd felt after Windom murdered Caroline, even if he hadn't quite put it into words at the time. Windom had been his best friend and partner - and he'd very nearly killed him alongside his wife. I took the boy right to the edge that time.

Cooper still has some unresolved feelings towards that. And while he definitely doesn't linger on that thought right now, it crosses his mind as he looks at her.

(It bothers him that he can so easily draw that kind of parallell between them.)

He sighs. And isn't sure whether he should ask or not, but in the end decides to - treading as lightly as he can.

"Did you know her before?"