I've been reading this with interest as a resident of Tucson for over 40 years living a few miles down Campbell and couple of blocks east. I'm not going to ask to be a verified insider because I moved away about 10 years ago and was never too familiar with the particular area NG lived in.
When I first heard about this case I kept thinking "Why does Savannah Guthrie sound so familiar?" then I realized it was not from her national role but rather I remember her from the TV news in Tucson in the 1990s. We also overlapped a little at the University of Arizona although I did not know her and it is very unlikely we had mutual friends.
To me this sounds like a true kidnapping for ransom because of SG's national celebrity. While this is rare in the US, it is relatively common south of the border. So my money is on cartels seeking nothing more than money. This could be a good thing for the eventual outcome because if they pay, a cartel may release NG just for street cred and future kidnappings.