The Nancy Guthrie case is now in its fifteenth day, as search and rescue teams continue to look for the 84-year-old, who has been missing since February 1.

Retired FBI agent Jason Pack has expressed serious concerns about the decision to use a laboratory 2,000 miles away from Tucson, Arizona, warning that time is critical for the vulnerable 84-year-old w

Authorities located a “possible biological laboratory" in a Las Vegas home on Saturday.

Nancy Grace criticized the investigation into Nancy Guthrie's disappearance amid reports of conflicts between local enforcement and the FBI. The legal commentator, 66, blasted the Pima County Sheriff's Department for "risking" the case,

Here's what we know about the South Florida DNA lab chosen over Quantico to analyze evidence in the Nancy Guthrie abduction.

FBI video forensics experts bring specialized equipment to missing Arizona woman Nancy Guthrie's home as intensive search operation enters day 12.

It remained unclear Wednesday why a suspected illegal bio lab in Las Vegas was not raided until last weekend, even though its owner was known to have ties to Southern Nevada as early as several years ago.

Nancy Guthrie, the mother of NBC Today show co-anchor Savannah Guthrie, has been missing for 12 days.

Pima County Sheriff Chris Nanos fired back on claims that he withheld essential physical evidence from the FBI in the disappearance of Nancy Guthrie. “Not even close to the truth,” Nanos told NBC Tucson affiliate KVOA on Thursday.

Las Vegas police and the FBI searched a home on the east side of Las Vegas Saturday morning, finding a "possible biological laboratory," including “refrigerators with vials containing unknown liquids.

By Jana Winter WASHINGTON, Feb 12 (Reuters) - An Arizona sheriff is blocking FBI access to key evidence in the investigation into the abduction of U.S. television journalist Savannah Guthrie's mother,