Grab a cup of coffee, citygirl! This is my story and I'm sticking to it (for now)!
I believe that past behavior is the best predictor of future behavior.
FD quickly moved on from Wife #1 to #2 Jennifer, a woman of wealth with access to huge trust funds which would only grow with each child, not to mention a father who would invest heavily in his dreams.
When the f-i-l died and the gravy train seemed to be ending, I believe FD behaved according to form and sought out a fellow grifter in #3 MT, someone who would help him drive Jennifer over the edge, getting him access to the trusts. Of course, the children were just necessary leverage to get those funds. (A guy's gotta' do what a guy's gotta' do.)
Because Jennifer had a support system (God bless GF!), she was finally able to surreptitiously get herself out from under FD's thumb, so he and his partner in crime (#3) had to maneuver doing away with her permanently.
For months they pondered the best way to do that without their involvement being obvious, a staged suicide being the perfect choice (thus eliminating the barrier between FD and the trust funds).
So the perfect plan was for FD to lie in wait at the house that morning.
Whoops! Jennifer fought back when FD tried to cut off her air supply in some way. I think she ran back toward her car and that he hit her with a blunt object. If we learn that the knife seen in Hartford was from her kitchen, he must have gone inside to get it to finish her off (leaving his DNA on the faucet with her blood).
Then things got hairy (pardon my pun since we know he had shaved himself). The suicide idea bit the dust with blood everywhere. Clean up had to happen and bloody stuff had to disappear, never mind what to do with Jennifer's obviously not-suicided body!
More detail-oriented and wiser WS posters have explained the details after this so I'll defer to them and
get back to your question.
Why do I think MT would have been in FD's rearview mirror? Why would he have planned to dump her?
Simply because her purpose had been served and she now brought little to the table. (Having knowledge of Jennifer's murder might put a kink in her longevity though, right?)
If FD gets off, he may gain access to the trust funds through the children, depending on how they're set up.
If he doesn't gain access, he'll move on and troll for #4. Watch your daughters!
If he's in jail, #4 will be drawn from a group of pathetic women, hybristophiliacs, who seek out prisoners online. She will send money to his commissary account, ensuring his access to Beanie Weenies and good soap.
ETA for your amusement:
“Hybristophilia” is a recognized psychiatric condition in which a person—usually a woman—experiences strong sexual desire for a man known for crimes that society considers repulsive. The “-philia” comes from a Greek word meaning “love for,” while “hybristo-“ is derived from Greek verb meaning “to commit an outrage against someone.”
Most definitely MOO.