Federal investigators are examining new details in the abduction of Nancy Guthrie, the 84-year-old mother of Savannah Guthrie, after evidence surfaced suggesting a masked suspect may have approached her Arizona residence more than once before she disappeared.

Guthrie was taken from her home in the Catalina Foothills area near Tucson, Arizona, on or around Feb. 1, according to authorities. The FBI previously released photos and video on Feb. 10 showing a man at the front door of the property wearing a mask, carrying a black Ozark Trail Hiker Pack backpack, and equipped with a handgun holster.

On Monday, the surveillance material made public by federal officials was not all recorded on the same day. According to a source familiar with the investigation, the photos and video released by the FBI were captured on two separate days, and the masked individual was not wearing a backpack in one of the earlier images.

Investigators are considering the possibility that the suspect initially approached the residence on an earlier date, noticed the home’s Nest doorbell camera, and left without further action. Authorities believe the individual later returned and was seen tampering with the device and placing branches in front of the camera lens in an apparent effort to obstruct its view.

The FBI has described the suspect as a masked man carrying a black backpack and wearing a handgun holster. Authorities are offering a reward of up to $100,000 for information leading to Guthrie’s safe recovery or to the arrest and conviction of those responsible.

The investigation remains ongoing as federal agents continue reviewing surveillance evidence and seeking public assistance in identifying the suspect.