You don't know for sure unless you1) research the title; or 2) deal with someone local. Within the last 30 days the Times-News ran a story about this activity in our community. Houses that were listed for sale were offered for rent by scammers who charged the typical upfront rent and fees and disappeared. "Renters" learned of the scam when they tried to move in. On the other hand, there are legitimate reasons why a person from elsewhere would have the authority to rent a house, as in an estate situation, for instance. Helpful questions to the out of state party would be "who is the owner, and what is your relationship to the owner." Information about the public record of ownership can be obtained through the Twin Falls County Office of the Assessor, and is searchable by street address.
You are correct to be very careful.
Best wishes for a favorable outcome, and please remember to designate a best answer.
This answer is offered as a public service for general information only and may not be relied upon as legal advice.