Motive? Doubtful. That would be more likely in a circumstantial case. But if this is indeed a DNA case, they aren't likely to develop a motive narrative in the PCA. They'll save that for the showmanship of trial. They'll probably develop at least some of the timeline in the PCA -- I think we'll definitely hear a lot more about the travels of the Elantra.
There's usually a strategy in crafting charging documents -- they'll try to include enough info to satisfy a judge that there's probable cause, without revealing more of their hand than they're ready to show.