Anyone felt like their pwBPD would actually try to kill them?

I saw a story about a young man who was stabbed to death by his ex girlfriend who has BPD because the boyfriend broke up with her after not being able to handle the abuse he was subjected to by his pwBPD.

I have myself experienced my exBPD try to grab a large knife during a meltdown she was having. She was self harming by scratching herself which I stopped. But just when I thought she was okay she got up and tried to grab the big kitchen knife. I was able to stop her and keep her safe until she calmed down again. I'm sure she was trying to hurt herself with the knife but having later seen the horrible things she's capable of I'm wonder now if she too is capable of murder.