International Private Investigator Jay Armes III and forensic psychologist Dr. John Delatorre analyze a new video the FBI is investigating as a possible connection to the Nancy Guthrie case on 'The Will Cain Show.'

TUCSON, Ariz. — The FBI announced on Thursday it is doubling its reward to $100,000 for information leading to the arrest of anyone involved in Nancy Guthrie's disappearance after releasing new details about a potential suspect.

FBI Phoenix said new "identifying details" about Guthrie's potential abductor have been confirmed after a forensic analysis of the doorbell camera footage by the FBI’s Operational Technology Division. 

The suspect is described as a man, roughly 5 feet 9 inches to 5 feet 10 inches tall, with an average build. 

Officials also specified the brand of backpack the suspect was seen wearing in a video released Tuesday, confirming it was a black, 25-liter "Ozark Trail Hiker Pack" backpack.

FBI NANCY GUTHRIE BILLBOARD CAMPAIGN AIMS FOR 'CRUCIAL PIECE OF INFORMATION'

The FBI released new photos of a backpack in relation to the Nancy Guthrie investigation on Thursday. (FBI Phoenix via X)

The search for Guthrie has stretched into its 12th day, as authorities scramble to locate the 84-year-old mother of NBC host Savannah Guthrie.

A U.S. law enforcement source told Fox News Digital on Thursday Pima County Sheriff Chris Nanos, who is leading the Nancy Guthrie case, is blocking the FBI from key evidence, as first reported by Reuters.

The source said the FBI asked Nanos for physical evidence in the case, including a glove and DNA from Guthrie's home, to be processed at the FBI's national crime laboratory in Quantico, Virginia, but Nanos has "insisted instead on using a private lab in Florida."It is unclear why Nanos may have requested the use of a private lab.

NANCY GUTHRIE SEARCH LIVE UPDATES: SECOND ALLEGED RANSOM NOTE DEADLINE PASSES AS INVESTIGATORS PURSUE ‘NEW LEADS’

The FBI released new photos of a backpack in relation to the Nancy Guthrie investigation on Thursday. (FBI Phoenix via X)

Since Guthrie's disappearance on Feb. 1, the FBI said it has collected over 13,000 tips from the public related to the case. 

Every tip is reviewed for credibility, relevance, and information that can be acted upon by law enforcement, officials said.

Threat Intake Examiners at the National Threat Operations Center (NTOC) and FBI personnel are supporting a 24-hour command post in which dozens of agents and investigators are assigned leads and tips to action each shift.

CLICK HERE TO DOWNLOAD THE FOX NEWS APP

Anyone with information is urged to call 1-800-CALL-FBI or submit tips at tips.fbi.gov.

Alexandra Koch is a Fox News Digital journalist who covers breaking news, with a focus on high-impact events that shape national conversation.

She has covered major national crises, including the L.A. wildfires, Potomac and Hudson River aviation disasters, Boulder terror attack, and Texas Hill Country floods.

The hottest stories ripped from the headlines, from crime to courts, legal and scandal.

By entering your email and clicking the Subscribe button, you agree to the Fox News Privacy Policy and Terms of Use, and
        agree to receive content and promotional communications from Fox News. You understand that you can
        opt-out at any time.

Subscribed

You've successfully subscribed to this newsletter!