Walmart sales records become critical evidence as FBI investigates Nancy Guthrie's disappearance

TUCSON, Ariz. — A single backpack has become a critical focal point in the investigation into Nancy Guthrie’s disappearance, prompting federal authorities to comb through Walmart sales records and store surveillance footage in search of a break.

Investigators are working with Walmart’s corporate security team while agents canvass stores across the Tucson metropolitan area, according to retired Supervisory FBI Agent Jason Pack, who described the strategy as a methodical effort to narrow the universe of possible suspects.