Sheriff Chris Nanos of Pima County, Arizona, tells CBS News that investigators searching for Nancy Guthrie believe the clothing and face mask worn by the suspect in the chilling doorbell video released last week were purchased at Walmart. 

They are still working to identify each brand. CBS News first reported that the suspect’s backpack, identified as a black Ozark Trail Hiker, was sold exclusively at Walmart.

It remains unclear whether the items were bought online or in-store in Arizona or elsewhere. The sheriff said investigators have spent several days reviewing surveillance video at local Walmarts.

Guthrie, 84, the mother of “Today” show co-host Savannah Guthrie, has been missing since Feb. 1. Authorities believe she was abducted from her home in Tucson in the middle of the night.

Nanos called the backpack one of the most promising leads in the case.

Walmart has provided records of all Ozark Trail Hiker online and in-store purchases over the past several months, including sales beyond the Tucson area, to investigators.

CBS News reached out to Walmart corporate offices, but a spokesperson declined to comment. 

Investigators believe the face mask the suspect wore is black but appears lighter on the video footage due to Nest camera’s infrared technology.

DNA evidence on glove

Meanwhile, authorities are conducting DNA testing on a black glove found near Guthrie’s home which “appears to match the gloves of the subject in the surveillance video,” the FBI said in a statement on Sunday.

The FBI said it received preliminary results of DNA testing on Saturday, and once those findings were confirmed it would enter what it called “the unknown male profile” into CoDIS, the FBI’s national database for matching DNA profiles.

The bureau previously described the individual as a male with an average build who is about 5 feet, 9 inches to 5 feet, 10 inches tall.

Investigators have also collected other DNA evidence from Nancy Guthrie’s property as part of the ongoing investigation, but the results have not led to a suspect, according to Nanos.

Multiple law enforcement agencies spent hours Friday evening searching a residence less than two miles from Nancy Guthrie’s home.

Nanos told CBS affiliate KOLD that the activity was the result of following up on “a lead that led to a search warrant and no arrest.” Authorities did not release other details on what led them there or what, if anything, may have been found.