[wimpycat]

Speaking only for myself, I'm only interested in discussing the more probable, not the more improbable scenarios. I'd need to hear of some evidence or hint of something notable before I'd consider alternative theories. For instance, if it comes out that Scott was a gambler, I'd be more willing to consider the loan-shark theory. Also, I didn't seriously consider that a physical fight may have led to Laci's death, until I heard about Laci getting convicted of felony assault when she was a teenager. Now that I know she's been proven capable of getting violent over a man, so I wouldn't be surprised to hear that Laci and Scott may have gotten into a fight that resulted in fisticuffs and he may have hit her and knocked her down, causing her to hit her head maybe, and then he took his chance and either finished the job, or just panicked and concocted this whole story to cover up for it.

[Yeti]

Now that I know she's been proven capable of getting violent over a man, so I wouldn't be surprised to hear that Laci and Scott may have gotten into a fight that resulted in fisticuffs and he may have hit her and knocked her down, causing her to hit her head maybe, and then he took his chance and either finished the job, or just panicked and concocted this whole story to cover up for it.

But you reject out-of-hand the possibility that it was a fight with another woman, which is the most obvious analogy to what happened in high school.