The FBI is re-examining DNA evidence from 84-year-old Nancy Guthrie’s Tucson home in hopes of a breakthrough in her disappearance.
A previously collected sample was sent for advanced testing using newer technology to help identify a suspect. Surveillance footage shows a masked, armed person tampering with her doorbell camera around the time she vanished, and blood found on the porch was confirmed to be hers.
Investigators are also analyzing a mixed DNA sample from inside the home, which is harder to isolate. Multiple labs across the country are assisting, but progress has been slow as authorities continue to follow leads in the case.