And sometimes you have evidence that corroborates a witness account and sometimes you have witnesses who agree on key elements. That is why you have a trial.
However, there may not be a trial in this case if the defense wins their pre-trial motion to dismiss. Since the pre-trial motions will be before judge Nail, the same judge who openly ridiculed the prosecutor, Valeska, at the bail hearing, there is the possibility that he may pre-disposed towards the defense. It was also Judge Nail who put a home monitoring device on Watson, where the charge is a capital murder charge, which is probably rare, if ever done. You have a prosecutor whose public reputation is severely tarnished. There will also be an underlying, unspoken motive to save the state the huge expense that will be involved in this case.
We will find out at the end of April. Personally, I don't think things look good for a trial under these conditions. I think Tina's parents need to prepare themselves for this very real possibility. My heart goes out to them. There is no doubt that they have suffered greatly from the uncaring, lying, outrageous, slimy behavior of their former son-in-law which was witnessed and reported by numerous people, not just Tina's family and friends.