Nancy Guthrie, 84, was kidnapped on Sunday, Feb. 1.
The search is ongoing for 84-year-old Nancy Guthrie, the mother of "Today" show host Savannah Guthrie, who investigators say appears to have been kidnapped from her Tucson, Arizona, home in the early hours of Sunday, Feb. 1.
The FBI has released photos and videos of an armed person in a mask in front of her home, appearing to tamper with a security camera.
Anyone with information is urged to call 911 or the Pima County Sheriff's Department at 520-351-4900.
Click here for the detailed timeline of the investigation into Nancy Guthrie's disappearance.
The FBI and the Pima County Sheriff’s Department are looking into a video posted online that shows a man in a backpack about 5 miles from Nancy Guthrie’s house shortly before her abduction, sources told ABC News.
The backpack on the video may be different from the backpack in the doorbell camera footage from Nancy Guthrie’s house, sources said.
-ABC News' Aaron Katersky and Trevor Ault
Investigators arrived at Nancy Guthrie’s home on Thursday morning to briefly erect a white tent -- typically used for privacy -- outside her front door.
Investigators took the tent down after about an hour and drove away in unmarked vehicles with a large pelican case labeled "video forensics." They also carried what appeared to be a laser measuring device.
-ABC News' Aaron Katersky
In a new Instagram post on Thursday, Savannah Guthrie shared an old home video from her childhood, showing her and her sister with their mother, Nancy Guthrie. The video is followed by a still photo of all three siblings with Nancy Guthrie.
"[O]ur lovely mom," Savannah Guthrie wrote in the caption. "we will never give up on her. thank you for your prayers and hope."
The Pima County Sheriff's Department is now asking Nancy Guthrie’s neighbors to check their home security cameras for footage from an earlier timeframe than the early morning of Feb. 1, when she was likely abducted.
Investigators on Thursday asked homeowners for video footage from Jan. 11 between 9 p.m. and midnight. They did not specify why.
They also asked for footage from Jan. 31 between 9:30 a.m. and 11 a.m. Authorities said there was a suspicious vehicle on a nearby street around 10 a.m.
The request came through the app Neighbors.
-ABC News' Aaron Katersky
