Three weeks before Nancy Guthrie's apparent abduction from her home in Tucson, Arizona, a masked man resembling the one suspected of taking her was seen on her front steps, according to multiple law enforcement sources.
Guthrie, the 84-year-old mother of "Today" co-host Savannah Guthrie, is believed to have been abducted against her will in the early hours of Feb. 1, according to the Pima County Sheriff's Department.
On Feb. 10, the FBI released surveillance images recovered from her Nest doorbell camera. As Fox News Digital previously reported, one of those pictures was taken on a different date than the others, according to another source with knowledge of the investigation.
Authorities have, at different times, asked for neighbors to check their home security systems for the entire month of January, the night of Jan. 11, and the hours surrounding Guthrie’s disappearance, between Jan. 31 and Feb. 2.
Jan. 24 has also emerged as a date of interest, News Nation reported last week, citing a neighbor who said she was asked for video from then, too.
"We don't know what that indicates, obviously, but the most hopeful read on it is that they're looking at somebody and that they're trying to place that person or persons in the vicinity at that hour on those dates to see if in fact, they can begin to work backwards," retired NYPD inspector and Fox News contributor said on "Fox & Friends" Wednesday morning. "Less hopeful, is let's say they have something in the forensics…that shows some kind of unusual activity that they're trying to hone in on."
The masked suspect remains unidentified. According to FBI analysts, he is around 5 feet, 9 inches to 5 feet, 10 inches tall and has a medium build. Authorities said he was wearing a 25-liter, black Ozark Trail backpack.
WATCH: Nancy Guthrie's Nest doorbell cam records masked suspect
Other items have not been officially identified, but he appears to be wearing a holstered pistol near his groin.
The Jan. 11 date is both when residents using the Ring Neighbors app reward of more than $1.2 million for information that leads to Nancy's recovery.
Anyone with information is asked to call 1-800-CALL-FBI.