Nancy Guthrie case: Can retail records help identify man in video? Experts say “specific backpack styles…”

The black-and-white photos and footage show a man wearing gloves, a mask, khakis, sneakers and a backpack who appears to be fiddling with a camera at Guthrie’s front door on the morning of Guthrie’s disappearance. One of the videos shows the man walking to the door with his head lowered. The person’s eyes are visible through the holes in the mask.

“Specific backpack styles, clothing brands, shoe types, even ski mask patterns – all of these can be traced through retail purchases, especially when purchased locally,” Dr. Gregory Veitch, retired supervisory agent and head of the FBI’s Behavioral Sciences Division, told Fox News Digital. “The FBI will investigate sporting goods stores, tactical stores and online purchase records.”

Even if the person is wearing a mask, law enforcement can use the latest technology to find their identity, Veitch added.

Learn more | Where is Anne Guthrie? Hours after the video of the subject was released, police conducted a search warrant in the Tucson neighborhood where Nancy’s daughter lives.

“They will also run the images through facial recognition systems,” Veitch said. “Even while wearing a mask, their visible eye structure, possible beard and body mechanics can generate investigative clues.”

Details of other items could also give investigators clues to the man’s identity, such as gun holsters and the type of gear they were carrying.

“Now that we know what he looks like and how he behaves, investigators will cross-reference this profile with Nancy’s life,” Veitch said. “Who has the tactical background, firearms proficiency and combat capabilities that we’re seeing?”

Once investigators are able to identify specific items worn by a subject, law enforcement can begin investigating brick-and-mortar and online retailers to narrow down the buyer.

Learn more | Nancy Guthrie suspect found? A manhunt is underway in Tucson, Pima County.

“Investigators are currently working backwards from those images,” former FBI agent Jason Parker told Fox Digital News. “If they can identify that backpack, that jacket, those specific items, they’re going to run purchase records from every retailer in the Tucson area.”

Parker explained that authorities will then focus on online retailers that have shipped items to local addresses. The search may also expand to include pawn shops and thrift stores in Tucson, “anywhere someone might have tried to discard gear after the fact.”

“Our goal is to establish a timeline of purchases, identify names and addresses,” he added.

Authorities could even use information about the clothing to better understand the man’s physical characteristics by focusing on the fit of items worn in the video. “They can learn about race, height, weight, body type and job status from the video,” Dr. Ann Walbert Burgess, a pioneer in the FBI’s Behavioral Sciences Unit, told Fox News Digital.

“The evidence is in the clothes,” Parker said. “If they find any of those items – backpacks, gloves, masks – they’re going to be looking for DNA, fingerprints, fiber optic transmissions in Nancy’s home. Even if the person is careful, it’s almost impossible when you have physical contact with a victim or a crime scene without leaving trace evidence.”

Veitch said he believes the man is native to the Tucson area. “He may have local connections and someone in his circle knows something that could solve the case,” he said.

The suspect in the case has not yet been identified. Nancy still missing.