There is no reason to believe her body had to have been taken to the lake immediately. She could have been stashed somewhere closer and taken to the lake later on.
There are age old motives---SA proudly lived out his motives for others to see, with his serial killer masks and his gore/horror music and love of gory films.
How about the tried and true 'motive' seen often, when Mom's live-in boyfriend gets interested in her sweet 13 yr old daughter?
What evidence was there that she actually ran away?
If she had been still alive and around for weeks or months, there would have been sightings. Kids aren't that smart or capable of keeping quiet.
Weird odd behaviour---like driving to work, that day, only to suddenly quit your good paying job, when you really need the money and the job?
The accusations against SA were unreasonable?
Who would have killed her over a custody arrangement?
As to the bolded above---it does not sound plausible to me.
Stashing somewhere intermediate could have happened but keep in mind that the S hit the fan the next day so it is not as though it would have been a simple thing to do. Where would such a place be? In any event, the time frame is still narrow even if such a thing did happen, and there is no evidence of any crime being committed in the house, or the car (the only one at his disposal) being used to move a body.
Having a passing interest in horror movies or true crime is not a motive, at least I hope not, otherwise I shudder to think what everyone here is getting up to in their spare time
There is no evidence of SA being interested in HD, other than the grandmothers claims that HD was uncomfortable around him. That does not mean some kind of sexual interest however, most teenage girls are uncomfortable when their mom's new boyfriend moves in.
There is no evidence that she ran away, but that was how the case was treated initially. There was no evidence of foul play, suspicions of foul play only emerged after she could not be found at the places where she might be expected to run away to.
There is no requirement for her to be alive weeks or months later, she most likely died or was killed when the story blew up on the news, since anyone involved at that point would have had a vested interest in making her disappear permanently since at that point someone was probably going to jail for a long time.
Quitting his job was not weird. If SA is to be believed, he had some sort of disagreement with his boss sometime prior to the christmas break (exactly when is not clear), so quitting on the first work day after would be not unusual or unexpected, especially for an immature guy basically being supported by someone else anyway. He was not upfront about it, claiming he was fired instead of quitting, because BD would most likely have gone ballistic if he told her he quit. So he told her something else instead.
The accusations against SA are unreasonable because there is literally no evidence that he did anything to HD or had any motive to do anything to her. The accusations leveled generally require that there be some sort of sinister convoluted plot to get rid of HD in the absence of any evidence to support that.
Usually the simplest explanation is the most obvious, namely that SA quit his job (or fired) and as a result was going to be at home permanently. HD, who did not like him being around anyway, got into a temper when she found out and left, going somewhere else. Then, whatever happened to her followed from that. SA would not have done that. He wanted a cushy life, not having to do work while an older woman supported him. Killing HD would guarantee that would not happen, so why would he? IMO SA quitting his job DID trigger subsequent events and set everything that followed in motion, but that does not mean he killed her or is to blame for what happened to her.
We know she disappeared after SA got back early from Big Spring, presumably he told HD that he was now unemployed, and this left HD POed since she did not want be around him all day. She left to "overnight with a friend" without warning, and at first BD did nothing about it, but the next day, after arriving at work and stewing on it for some time, suddenly called DD and told him to go get HD and make her come home. That is when all the public drama started, but domestically it probably had been going on in the home for a while. We don't know for sure, but HD and BD's actions suggest that there was a major discipline issue going on with HD. Some of this is from SA's account, you probably will take that with a pinch of salt, but BD's behavior over the period suggests that what happened was likely that since she did not question SA's account, she just accepted it and the only explanation for that is this is what she expected with HD's behavior at the time. It was not something just out of the blue, it was a behavior BD expected based on past experience.
People would not have killed over a custody dispute, but someone might get killed as a consequence of it. Let's face it, there was absolutely zero chance CD would have gotten custody of HD. He had a criminal record, was on probation IIRC, had a history with drugs, did not appear to have a permanent full time job as far as I can tell and lived with his girlfriend who was apparently on welfare. BD on the other hand had a decently paying stable job, had her own house and had no criminal record. There is no way custody of HD would have been removed from BD and given to CD under those circumstances. HD was staying where she was unless she relocated herself on her own initiative or got help from family or friends. This does not mean CD had anything to do with it, there are quite a few other family members or friends who might have taken it upon themselves to intervene in this way. And HD herself could have done it, she was not subject to much parental control and who knows what sort of people she may have been acquainted with.
In either case she would not have been able to go to the obvious places because the police would just have gone there and returned her home. So, to be effective she would have to be relocated to a third person or place without any obvious connection to immediate friends or family. And THAT, I believe, is where the problem began. She ended up be stashed with people who were pretty shady, the story blew up and when it did, the potential for serious jail time loomed, so they just got rid of her, took off themselves and acted like nothing happened. Maybe they killed her, maybe they pawned her off to someone else who eventually did it. She just sort of vanished and everyone involved denied knowing anything. And after she was dead/disappeared, the ones who helped her do this could not say anything otherwise THEY would be doing that jail time too, maybe even a trip to the gas chamber. So everyone shut up and was more than happy to let SA take the blame. After all, in their minds the events were kind of his fault anyway by quitting his job and starting everything.
And that is where we are now. I don't think SA had anything to do with, nor BD. The others, I am not so sure. It is entirely possible that all of them have the gist of it by now, even if not involved, but for various reasons have an incentive to keep their thoughts on that subject to themselves. Will WE ever know the truth? At this point I am kind of doubtful about that. Too much time has passed and the water muddied too much. We will have theories, speculations, but not much more.
