Key Highlights
- Nancy Guthrie, 84, went missing from her Tucson home.
- Investigators are requesting surveillance footage from January 11 and January 31.
- A video shows a bald man wearing a gray jacket and a backpack near her home on February 1.
- A forensic tent was previously set up at Guthrie's home after blood was found but has since been removed.
- Authorities are treating her home as a crime scene.


