The FBI is awaiting DNA test results that could identify the suspect in Nancy Guthrie's disappearance within hours.
A glove discovered roughly two miles from the 84-year-old's Tucson residence appears to match those worn by the masked gunman captured on her doorbell camera, according to the agency.
The local Pima County Sheriff's Office collected around 16 gloves near her home last week, sealing them in evidence bags before sending them to a Florida laboratory for analysis.
Most were discarded by search teams, but one stood out as matching the black nitrile gloves seen in the footage.
An unknown male DNA profile has been extracted from the glove, with results typically returned within 24 hours.
The FBI has so far described the unidentified man as someone with an average build and standing at around five feet, nine inches tall.
In the doorbell clip, he could be seen wearing a black ski mask and carrying a 250-litre Ozark Trail Hiker Pack backpack on his back.
He was also sporting black gloves - which could provide the DNA breakthrough.
Nancy Guthrie (right), the mother of US Today show host Savannah (left) was last seen entering her home through the garage on the evening of January 31 after dinner
|REUTERS
Before she vanished, 84-year-old Nancy made posts on a neighbourhood app which revealed she had endured run-ins with criminals outside her home.
The scares convinced her to buy the doorbell camera for her own protection, which eventually captured the masked suspect outside her home.
The mother of US Today show host Savannah was last seen entering her home through the garage on the evening of January 31 after dinner with her other daughter Annie and son-in-law Tommaso Cioni.
One source with knowledge of the investigation revealed to local outlet Arizona Family that detectives increasingly believe the abduction was actually a burglary that went wrong.
This theory has given investigators hope that Guthrie may still be alive.
Multiple experts who examined the doorbell camera footage from that night told Arizona Family the incident did not resemble a carefully-planned kidnapping.
LATEST ON THE HUNT FOR NANCY GUTHRIE:
Last Tuesday, officials released images of the suspect in her kidnapping for the very first time
| FBI VIA REUTERS
The man can be seen carrying a firearm in a holster as he creeps up to Nancy Guthrie's doorstep | FBI VIA REUTERSThe 84-year-old has not been seen or heard from since her disappearance, which has gripped the nation.
Several individuals have been questioned but subsequently released, while ransom notes demanding at least $6 million in bitcoin have been sent to media outlets including TMZ.
Former FBI agent Michael Harrigan told GB News of the suspect's "amateurish" behaviour just days ago - and also offered his thoughts on a motive.
"This could be an individual who potentially was hired to do a kidnapping by somebody who may not be well versed in this," he said.
Mr Harrigan noted that professional kidnappers do exist, particularly in Mexico and other countries where abduction for ransom operates as a business.
The FBI is expecting DNA results in a matter of hours
|REUTERS
The FBI has also released images of a black backpack wanted in connection with its probe
| FBI VIA REUTERS"There are professional kidnappers out there in the United States... You see some of them down in Mexico and other countries where they are professionals because they kidnap, in series, multiple people for monetary gain, to obtain ransom," he explained.
"It's a business," he added.
Harrigan suggested the suspect may have randomly selected Guthrie's home with the intention of committing a burglary.
"This individual could have been hired, or the other possibility is he maybe randomly picked a house to go into and was looking to burglarise it," he said.
The former agent pointed to the suspect's decision not to immediately remove the doorbell camera as significant.
"But the fact that he didn't knock the camera off the wall immediately... is an indication, anyway, that maybe he didn't want to disturb, Mrs Guthrie in the house. He didn't want to make a lot of noise," Mr Harrigan explained.