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

I have nothing to base this on, but my hunch is he offed himself. I have to think he's realized what he's done and to someone I think he probably cared about. Just have a hunch he might not be able to live with what he did.
It’s possible. But I tend to believe his body would’ve been found by now. I think he’s out of the country.