Sorry to drop this in the middle of what's going on. I'm so far behind, but I thought this was such a great post and actually moves us closer to what may have been going on terms of motive here.
I've just been flipping and reading through sites about female stalking and one of the things that surprised me was that when a female stalker decides to commit violence, she doesn't do it because of passion. It is entirely predatory and emotionless. Why that would be, I don't know since the female stalker is known for carrying huge amounts of hostility during the stalking phase. Perhaps, for the stalker, the object of their affections have been residing in their heads so obsessively that finalizing their internal plan to murder stops the obsessing?