My theory is that this is some kind of long distance online relationship gone bad.
I am not saying infidelity. This could have just been someone she played online with, maybe communicated through an online game chat (thus why no motive can be found through traditional methods such as text message/call history). This is also why her close circle of friends/family wouldn’t know of anyone who would want to hurt her.
At some point, the person she was talking to/playing with, may have had a spouse (suspect) who found out that her significant other was engaging online with another female (the victim), and took it out of proportion.
The suspect, at this point, is infuriated. They find out more information about the victim, her name, address, etc., and decides to take matters into their own hands. If the suspect lived a state away, it would only take a few days to carry out the murder and get back home.
So IMO this theory would explain why the suspect was so brazen with carrying out the murder. They didn’t really “care” who saw them, so long as they weren’t right in front of the victim’s doorbell camera (they could have seen the ring camera the night before when they scoped out the house, as they are pretty big and easy to see). By the time the suspect committed the murder, and took off in the truck, they would be long gone and back on the highway before dispatch could even get the call information entered, let alone put out a BOLO for the vehicle. If a neighbor happened to see them, would it matter as much if the suspect lived in another state? (If the suspect was wearing a disguise it would matter even less).
This theory would also explain why nobody locally can identify the truck, or at least if someone has identified this type of truck, it hasn’t gotten LE any leads.
It also explains why the murder seems to be so personal and emotionally driven, yet at the same time, it doesn’t seem like the victim has any idea (at first) who the suspect is.
The brief conversation before the gunshots could have been something along the lines of:
Victim: “Good Morning”
Suspect: Are you (insert name here)
Suspect: (Shows victim note that perhaps has the victim’s online username written on it to confirm that its her)
Suspect: “You know you’ve been talking to a married man/talking to my husband right”?
Victim: “Thats’s not true” (or she may have be silent at this point, maybe trying to deny, or maybe just too shocked at this point)
The suspect then shoots her.
This could also be why detectives had a POI who was located in Miami.
The victim’s husband being responsible doesn’t sit well with me. Reason being, if he and the suspect were working together to commit murder, in my mind, there would have been much more effective methods of doing it.
The million dollar question is, well how did the suspect know that the victim would be having a garage sale? Maybe the suspect didn’t know, and they were just waiting for the victim to leave for work. Maybe they were going to follow her to work and do it there. Maybe they were even bold enough to just go and knock on the door. Maybe they didn’t think that far into it, and just got lucky. While I do admit that showing up at that particular moment does seem coincidental, I don’t think it’s enough to say that the suspect knew for certain that the victim would be outside at that particular moment. If the suspect was willing to murder in the middle of a neighborhood, they were determined, and the time/place probably didn’t matter too much to them, as long as they could make a quick getaway.
A variation of this theory, is that instead of the suspect being a significant other, they could have been the person that the victim was directly involved with in the online relationship, and somehow the victim offended them. Perhaps the suspect was upset that the victim decided to end the relationship or cease communication, and thus carried out the murder. Maybe the suspect thought that something more would come from the relationship.
Sorry if all of this has been said before.