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.
Large retailers maintain SKU-level sales records that capture the date, time and location of each purchase, along with payment method information.
By isolating sales within a defined window, agents can create a list of purchasers and then prioritize leads based on physical descriptors.
Pack said retail forensics can be decisive when combined with other evidence.
"When you can match a product to a person through both data and video," he said, "you begin to shrink the suspect pool quickly."
Jan. 31, 2026
Between 9:30–9:45 p.m. — Family drops Nancy off at home
9:50 p.m. — Garage door closes (per authorities)
Feb. 1, 2026
1:47 a.m. — Doorbell camera disconnects
2:12 a.m. — Security camera detects motion
2:28 a.m. — Pacemaker disconnects from phone application
11:56 a.m. — Family checks on Nancy after she misses weekly church livestream gathering
12:03 p.m. — 911 called
12:15 p.m. — Sheriff’s deputies arrive at home