A strand of DNA recovered from Nancy Guthrie’s Arizona home is undergoing extensive testing at the FBI’s crime lab as the investigation hit the 100-day mark — and authorities continue to hold out hope for a break in the case.

The 84-year-old mother of "Today" host Savannah Guthrie is believed to have been taken against her will from her Tucson, Ariz., home in the early morning hours of Feb. 1 Don Arnold/WireImage; FBI Phoenix/X Federal investigators are using new technology to ...

PIMA COUNTY, Ariz. -- The FBI recently received and is now analyzing potentially critical DNA recovered months ago from the Tucson, Arizona, home of Nancy Guthrie, sources familiar with the investigation told ABC News. Nancy Guthrie, the 84-year-old mother ...

The FBI is now utilizing new technology to conduct advanced analysis on the DNA sample.

DNA evidence recovered from Nancy Guthrie’s home is being rushed to the FBI’s elite lab for cutting-edge analysis following earlier testing at a private lab, Wonderwall.com can report. The move comes two and a half months after the 84-year-old was taken from her Arizona home in the dead of night.

TUCSON, Arizona — The FBI is analyzing what authorities describe as potentially critical DNA evidence in the ongoing investigation into the disappearance of 84-year-old Nancy Guthrie, a case that has drawn national attention. The new round of testing ...

The FBI recently received and is now analyzing potentially critical DNA recovered months ago from the Tucson, Arizona, home of Nancy Guthrie, sources familiar with the investigation told ABC News. Nancy Guthrie, the 84-year-old mother of "Today" show host Savannah Guthrie, was abducted from her home early on Feb. 1.

Blood spatter evidence shows Nancy Guthrie made a last stand on her porch before being abducted, and the suspect made key mistakes, retired FBI agent says.