I really hope they keep both trials together. I've always found it a waste of time/money to have separate trials for criminals that are essentially being tried for the same crimes. I.e., it seems obvious that the deaths of both of their respective spouses & the two innocent children are crimes that they planned/orchestrated together.
I don't see how CD can get out of at least being complicit for the deaths of the two children - since the remains were found on his property. Going along with this, he tried to flee the scene (and was stopped) when his property was being searched - so it's evident that he knew/suspected they were going to find something.
Yes, I've had the misfortune to run into people like this as well. People like this make me sick.