It should also be reiterated that a murder/dump falls under the sheriff's/state jurisdiction, while a kidnapping and email ransom falls under FBI/federal jurisdiction. The sheriff's office, once the hub of media relations, paused daily press conferences a few days back, and this is despite the investigation clearly intensifying and public interest in it having multiplied exponentially. The FBI typically does not comment on their active investigations. This suggests a literal change in jurisdiction and oversight, and an implied change in what law enforcement agencies feel occurred that night and subsequently.
Indeed, the Guthries have been pleading with purported kidnappers to return their Mom, and acknowledging contact and their willingness to pay. The Sheriff was spotted at a basketball game last night. To be sure, there is nothing wrong with the Sheriff enjoying his life and any favorite past times, but this fact, along with the shift in media relations a few days ago at his department, does suggest that his office is no longer the key agency overseeing this case.
And if that is true, and the Guthries are clearly and publicly focused on a kidnapping and interacting with a purported kidnapper in order to negotiate the return of NG, then it suggests that this is what it seems to be - a kidnapping for ransom led by an always tight-lipped FBI.
JMO.