In my long life I have either been directly involved around abused women as a landlord, or as a boss of someone, or the friend of someone. In every case. Every last one. No matter the danger. No matter the abuse. The woman takes the abuser back in. Any time I sense this dynamic, I run away. There is nothing you can do to help. Nothing.
I would suspect that a significant majority of male on female domestic abuse consists of women willfully shacking up with men who have known criminal records.
From the information I have seen, the woman has not taken the abuser back for 15 years and has a lifetime protection order granted 15 years ago.
The Murderer did violate the order, but, apparently the woman never invited or permitted contact for 15 years.
Still investigating.