Young couple goes on van tour of US, boy comes back with van - no girl

If he was a smart criminal, she would have had an “accident” and he would have immediately called 911.

He’s just an idiotic screwup who has now dragged his parents into his mess.
Well...at least that is a case for it being Third degree murder/voluntary manslaughter instead of First degree murder (though Chuck would have to confirm). They both looked unhinged, and it wouldn't be surprising if he just flew off the handle and killed her...I could buy that story.