Let's take a look at a few things in this case;
First of all, when Lacey is "missing", he is all teary eyed, putting up "missing" posters and offering a reward for her return.
Then, when her body and the body of her child are found, where do they find Scott? Down by the Mexican border, with dyed hair, sporting a new beard, using his brothers ID, with $10,000 dollars cash (where did he get that?), ready to skip across the border and hide in Mexico. Why?
I don't like to convict a person without a trial and I believe "innocent until proven guilty", but his actions are not exactly indicitive of an innocent person, are they?
If he wanted to maintain the facade of an innocent person, I would think that as soon as the word was out that Lacey's body had been found, he would have been on the scene, with genuine tears in his eyes as he identified the body. But no, it took two or three days for DNA test to be done to positively identify her.
Innocent? I don't think so. Guilty? I guess we will have to wait for the jury's verdict.