Nancy Guthrie case: Suspect approached her door before the night of her disappearance, source says

The masked person seen on the doorbell camera footage of 84-year-old Nancy Guthrie’s Arizona home the morning she is believed to have been kidnapped was also at her doorstep on another night, a source tells CNN, another clue in the exhaustive, multi-week search for the mother of “Today” show host Savannah Guthrie.

The photos and video of the masked person on Guthrie’s doorstep — released by the FBI on February 10 — were taken on two different days, rather than just on February 1, when authorities believe she was abducted, the source said. That’s because the masked suspect is not wearing a backpack in one of them, according to the source.

ABC News first reported the suspect appears to have been at her door before February 1.

The Pima County Sheriff’s Department said in a statement Monday “there is no date or time stamp associated with these images” and “any suggestion that the photographs were taken on different days is purely speculative.” It added the investigation is ongoing and “conclusions will be guided by verifiable evidence and established facts.” CNN reached out to the FBI Phoenix office for comment.

Guthrie disappeared from her secluded Tucson home after she was last seen on January 31. Local, state and federal law enforcement surged to the area and have spent over three weeks scouring the unruly desert landscape for Guthrie or any evidence that could bring her back home.

Residents in Guthrie’s neighborhood were previously asked by the sheriff’s department to submit video as far back as January 1, but specifically focusing on two dates – January 11 between 9 p.m. and midnight, and January 31 between 9:30 a.m. and 11 a.m. The sheriff’s department specifically requested footage that includes cars, traffic, people or pedestrians, or anything that feels out of the ordinary or important.

The FBI released video and photos of a masked, armed man tampering with Guthrie’s doorbell camera the morning of her disappearance, producing thousands of tips in the process. The suspect is described as male, approximately 5’9” – 5’10” tall and having an average build, according to the FBI.

From that video, investigators were able to identify the man was wearing an Ozark backpack, according to the Pima County Sheriff’s Department, but are still trying to identify other items and where they might have been purchased.

Some investigators have visited gun shops in the Tucson area as the suspect in the video is seen wearing a gun holster that the sheriff said “had some pretty unique characteristics.”

In addition to the request to those living in the area, authorities have canvassed residences, businesses and government agencies for surveillance video to identify any possible indication of where Guthrie may have been taken, a law enforcement official familiar with the case says.

Investigators continue to review “thousands of hours” of video obtained from the greater Tucson area, the source added.

They also continue to run lab analysis on DNA found at Guthrie’s house, Pima County Sheriff Chris Nanos said Thursday. DNA on gloves found 2 miles from the home, one of approximately 16 gloves found in the search to comb the area surrounding Guthrie’s home, did not return any matches in the national database known as CODIS, and doesn’t match DNA found the house, either, Nanos said.

Law enforcement has also detained, and later released, two people as part of the investigation, the sheriff’s department previously said.

Despite these developments, investigators have no leading theory about a motive, according to a source. But authorities say they believe Guthrie was removed from the home against her will, and the sheriff said authorities have not ruled out the possibility more than one person may have been involved.

But the search persists. As recently as Saturday, detectives and agents were back canvassing in Guthrie’s neighborhood, the Pima County Sheriff’s Department said, although it didn’t share details of what spurred the return.

Her children, including Savannah Guthrie, have repeatedly pleaded for her return. They have taken to social media in several videos in an attempt to address purported ransom notes sent to several media outlets, as well as asking the public for help in her search. Despite the reports of the ransom, neither the family nor law enforcement have confirmed if they were real or if they made contact with the sender.

The sheriff has said that none of the family members, including siblings and spouses, are possible suspects in the case.

There are currently two rewards available for information related to Guthrie — one of up to $102,500 for information leading to an arrest in the case from 88-Crime, the Pima County and Tucson affiliate of the national Crime Stoppers organization, and an FBI reward of up to $100,000.

If you have information that could help investigators, you can call 1-800-CALL-FBI or 520-351-4900. You can also submit information at tips.fbi.gov.

This story has been updated with additional details.

CNN’s Ed Lavandera and Josh Magness contributed to this report.