I don't "victim bash", but it does take two people to be in a relationship. If a relationship is abusive, or addictive/dysfunctional, one person has the responsibility to leave. Especially if children could be in danger.
I don't buy that this guy just woke up and decided to kill his family. There are indicators, and obviously SW knew there were problems, she left for 6 weeks, comes home, and leaves again. That seems to be an indication to me that she didn't want to be with CW. The quick response by her friend, is also an indication that her friend knew that there were problems.
If you know someone in an abusive relationship, dysfunctional relationship, give them this opportunity, to save their lives, and leave.
This is not being alarmist, it is a very thin line, when dealing with someone who has anger management problems, a low self esteem, between an argument and it goes too far...in an Instant, especially if alcohol is in the mix. I know, I have been there, and I left. The money, the house, at that point, nothing mattered.
I am sorry she is dead, and her babies are dead. It was horrible. CW killed them. But did she have a chance to leave?