Retail records could unmask potential subject in Nancy Guthrie case as experts reveal 'clothing is evidence'

Several law enforcement experts suggest the individual's clothing could give investigators new leads to follow as they attempt to track down the subject in the video. 

"The specific backpack style, clothing brands, shoe type, even the ski mask pattern - all of these are traceable through retail purchases, particularly if bought locally," Dr. Gregory Vecchi, retired supervisory Special Agent and Chief of the FBI Behavioral Science Unit, told Fox News Digital. "The FBI will be canvassing sporting goods stores, tactical supply outlets and online purchase records."

Vecchi went on to add that even though the individual in the video is wearing a mask, law enforcement can use updated technology to pinpoint their identity. 

"They'll also be running the images through facial recognition systems," Vecchi said. "Even with the mask, their visible eye structure, possible mustache and body mechanics can generate investigative leads." 

The details of the items worn by the subject can also offer clues to investigators regarding their identity, such as the gun holster and type of gear they are carrying.

"Now that we know what he looks like and how he operates, investigators will be cross-referencing this profile against Nancy's life," Vecchi added. "Who would have the tactical background, the firearms proficiency and the operational capability we're seeing?" 

Once investigators identify specific items worn by the subject in the surveillance footage, law enforcement can then begin to canvas both in-person and online retailers to narrow down who has purchased the items seen in the video. 

"Right now investigators are working backwards from those images," former FBI agent Jason Pack told Fox News Digital. "If they can identify that backpack, that jacket, those specific items, they're running purchase records from every retailer in the Tucson area."

Pack added investigators will then turn their attention to online retailers - such as Amazon - that have delivered the items to local addresses. 

"The goal is to build a purchase timeline that leads to a name and address," Pack said.

"They can get race, height, weight, body-build and work from the video," Dr. Ann Wolbert Burgess, who pioneered the FBI's Behavioral Science Unit, told Fox News Digital. 

"Clothing is evidence," Pack said. "If they recover any of those items - the backpack, gloves and mask - they're looking for DNA, fingerprints, fiber transfers from Nancy's home. Even if the person was careful, it's nearly impossible not to leave trace evidence when you're in physical contact with a victim or a crime scene." 

Ultimately, Vecchi believes the subject seen in the surveillance footage is native to the Tucson area and the case hinges on someone recognizing them based on the images released to the public.

"He likely has local connections, and someone in his circle knows something that can break this case open," Vecchi said. 

The FBI told Fox News Digital it has not identified a suspect or person of interest in the disappearance, and continues to urge the public to come forward with information.