Nancy Guthrie Latest: Investigator Announces 'Good Lead'

The search for Nancy Guthrie is now in its fifth week, as authorities continue to sift through leads and explore new avenues in an attempt to locate the 84-year-old mother of Today cohost Savannah Guthrie.

Nancy Guthrie disappeared from her residence in Tucson, Arizona in the early morning hours of Feb. 1. New surveillance video, taken between midnight and 6 a.m. outside a house roughly 2.5 miles from Guthrie's, shows several cars driving through, including around the time the missing woman's pacemaker last synced.

In a new interview, retired NYPD detective David Sarni called the footage "a good lead" and "better than we’ve had so far."

New footage could prove significant

Sarni told FOX 5 that the early morning surveillance video "is something that may be valuable to find out how they abducted Nancy and took her away," though he did also call for caution.

"We cannot even determine whether or not those vehicles that were located on that camera connect to the house yet," Sarni said. "I always tell people, wait until the experts do that."

The surveillance images were obtained by Fox News Digital from a home outside of the original 1.5-mile radius authorities canvassed following Guthrie's disappearance.

"You’re seeing a lot of changes with the dynamic of the investigation," Sarni added. "It’s now expanded even further than the 1 1/2 mile area to two miles, maybe go a little farther than that."

Rewards remain in place

Both the FBI and Guthrie family are offering significant rewards, with the bureau advertising $100,000 for information and Savannah Guthrie announcing a $1 million prize last week.

“We need to know where she is. We need her to come home. For that reason, we are offering a family reward of up to $1 million for any information that leads us to her recovery," Savannah Guthrie said in a video on Instagram on Feb. 24.

“All of the information about this reward and the details are in the caption below. You can call the 1-800 tip line. You can be anonymous if you want. Someone out there knows something that can bring her home. Somebody knows. And we are begging you to please come forward now.“

The $1 million offer came after Pima County Sheriff Chris Nanos reportedly discouraged the Guthrie family from putting forth that large of a reward in the early stages of the investigation. Things have changed though, explained Sarni, resulting in the need to look for "bad actors."

"Maybe that will have those bad actors who may have been tertiarily involved, who don't want to get arrested, may be involved in this and get those tips," he added.