84-year-old Nancy Guthrie was reported missing from her home in Arizona on February 1.
In video footage released by the FBI, a masked, armed person is seen outside Nancy Guthrie's door in connection with her disappearance.
One person was taken in for questioning, and police searched a property connected to that person in Rio Rico, Arizona.
Savannah Guthrie writes on social media that she believes her mother is still alive and is appealing to the public for help.
