JMO, but I think CW may have had an issue with his father, and I think that may be relevant in the context of his motive for committing these murders.
He asked to speak to his father before telling his version. I think that shows his need to get his father on board and convince him. I think that is unusual in a man of CW's age, to need to persuade his father. It is an assumption I am making based on knowing that his father would get to hear what his version was like the rest of us did anyway. I think he had a need to justify himself personally to his father, which suggests a huge dependency on what his father thinks and possibly a feeling underpinning that of not meeting father's expectations.
If I juxtapose that with CW killing his entire family, and trying to set a scene in which they had all left him, it may be that he could not face his father's reaction to him abandoning Shanann, their future unborn son, and his daughters for a new partner. Extreme, but I believe that he hadn't cut the cord so to speak and my opinion is that a strong attachment to parental judgment can point to unresolved and troubling issues stemming from childhood.
This post isn't intended to cast any blame towards his parents.