Yes, you are correct. That and the text messages from CA show guilt.
The burden of proof is still on the police/FBI. Until they find a body, she is just a missing person.
Frankly, finding a body in the deserts of the SW US is literally a needle in a haystack. Especially, if he drove off on some side road miles out into the desert.
Remember the intern that went missing in Washington, DC?
She was having an affair with some CA congressmen. She went missing and her bones were found in Rock Creek Park right in DC about a year later. My point is DC has millions of people in it. Thousands are in Rock Creek Park everyday. If it was not for a guy walking his Golden Retriever in just the right place she may not ever have been found. IF this girl is buried out in the desert somewhere, she may never be found.
Yep, I’ve seen Casino. :-)
Unless the van has gps or their phones pinged or a half dozen other ways the feds can trace their whereabouts.