At times it feels like it's turning into this weird cluedo game with very limited list of suspects and full confidence that surely either one of them did it or some of them (or even all of them) conspired, as there is actually no physical way for anyone else to commit the crime.
One of VI said that Cotton wasn't that nice of a man to give his SIL rides just for the sake of Rachel going shopping.
But in the same time - he could be unaware that's the reason behind it, and do that just out of habit or cause he liked to see how the work is going, just look around or pick up something on the way. We know nothing about his habits.
It's not like the whole ordeal can't be explained in a stupid and mondain way. Let's say:
1. DA was home all day, before she went to pick TT up from bowling alley.
2. CA actually gave TT ride to and back from work cause at the time he hasn't take his treatment YET... or at all. Cause again, we don't know what kind of person he was when it came to healthcare. We know that he didn't have insurance (at all or good enough to cover all the medical bills) so we don't know if he was like "oh, I'm supposed to take it today, so 100% I have to take it today" or more of the type "oh, I'm supposed to take it today, but I don't want to be all sick on Christmas, so we will actually do that on 26th".
3. If the neighbour actually, physically lived NEXT DOOR from A's it'd be pretty hard for her to watch A's driveway.
23rd is not the time to set outdoor decorations. And doing stuff at home would likely require getting pretty close to the window to look outside and check what's going on in the street.
Possible, some people do that - but we don't know if she really claimed that or not. Could be that she only compared usual workdays when FA wasn't around and car wasn't in their driveway most of the day and just missed Fran's brief visit in the workshop in the morning as well as 1,5h long absence later.
At the time when they made all those statements, if innocent, they could have no real clue of how serious it is and that they won't ever see the girls again. There could be some dumb motive behind all this mess - like sudden fear that now it could be all over the newspapers that they say that CA was givin people rides and kinda going to work on the day when he was supposed to be taking treatment. They were likely way less scared than other families cause:
1. Rachel was 17
2. They had experience with DA running away previously, multiple times, and she was coming back safe
so unlike Julie's mom or Wilson's - they had reasons to think/hope that it may be not that serious.
It's all so weird, it all feels so stretched.
But in the same time. Scenario like:
1. Guy is angry and jealous about his teenage wife.
2. He snaps on the day and at the time when he's 100% sure that she's not alone.
3. Finds her
a) in company of two younger girls at the Mall and forces them to go with him... but where?
b) at home, where her sister temporarily lives, with two other people living in their backyard and also with ex and in-laws possibly showing up at random times.
4. Murders her.
5. Murders them too.
6. But he's so lucky that her sister is just there, ready to jump in and help him dispose of the bodies cause they went to highschool together and dated briefly, while he was still married to his ex.
7. They figure that in order to stop LE from investigating anything too soon they need to fake a letter that will explain the sudden disappearance, but they fail to make anything right.
8. His inlaws realize what he did and also jump in to help cover for this triple murder of their daughter, their friends only daughter and one other little girl.
I know that things point at that being completely or partially accurate, but it's too stretched to last 50 years. It sounds like lousy Borgias and so unlike any other crime I ever heard about. Scenarios like that usually make sense just because some important factors are missing.