Assuming Douglas is a spouse abuser, a bully - he would stop at nothing to gain control. Filing for divorce on 'his' terms with 'himself' in charge gives him the control he needs to have at the time.
Spending money to get that control is irrelevant for the abuser - whatever it takes, including murder, is what he resorts to. Add to the pot, violence, arrogance, narcissism, the obsession to control, and manipulative behaviors - you have the recipe for murder.moo
The whole business of control is an obsession that can lead to murder. The survivor of the obsession should truly be congratulated. moo
You could equally well say that about the wife and there is enough in the history of this couple to suggest that may be true as well. The bottom line is at this point we don't have enough reliable information to know which version is true.
This case is an odd one, on one hand it would appear to fit a familiar pattern but on the other hand there are elements that seem very weird. But, now that LE have the vehicles and I'm sure they are investigating his alibi, we will probably know if he is involved or not by next week. If he is involved then then the general timeline will be established pretty quickly, if he is not involved then the investigation will be back to square one and focussed more on what was happening in the area where she lived.