Nancy Guthrie Sheriff Insists Investigators Are Closer To Solving 84-Year-Old’s Disappearance—as Case Hits Grave Milestone

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The sheriff leading the investigation into Nancy Guthrie's disappearance has claimed that authorities "are closer" to solving the case—100 days after the 84-year-old vanished from her Arizona home.

In a very brief interview with Fox News, Pima County Sheriff Chris Nanos was asked whether cops are making any significant headway in the investigation and if they feel they're getting "closer" to solving it.

"We are," he responded, adding that they have recently made some "really great" developments in their investigation.

Nancy, who is the mother of "Today" show host Savannah Guthrie, went missing from her Tucson-area home in the early hours of Feb. 1, having last been seen by her daughter, Annie Guthrie, and her son-in-law, Tommaso Cioni, on the evening of Jan. 31.

Security camera footage taken from a Nest camera mounted at her front door later revealed that a masked and armed intruder had been seen approaching the property at around 1 a.m. on the day she is thought to have been abducted from her home.

A large-scale investigation involving both the Pima County Sheriff's Department and the FBI has been underway since that date, however authorities have come under fierce criticism for the apparent lack of progress made thus far.

Anyone with any information about Nancy Guthrie's case should call 1-800-CALL-FBI, 520-351-4900, 88-CRIME, or visit https://tips.fbi.gov/.

The last significant update in the case came in mid-April, when it was revealed that the FBI had received "potentially critical" DNA evidence found inside Nancy's home.

On April 16, FBI sources told NewsNation and ABC News that its official laboratory has received a DNA sample that had been undergoing testing in a private lab in Florida.

The insider noted that this DNA evidence is not new, but rather has been extracted from a variety of materials that was collected from Nancy's dwelling in early February. That evidence had previously been sent to a laboratory in Florida by the Pima County Sheriff's Department and has only now been returned to the FBI bureau.

"There is no new DNA evidence in the Nancy Guthrie case. The FBI requested this material over two months ago," an FBI official told ABC News.

"The Pima County Sheriff's Office sent it to a private lab in Florida. Eleven weeks later, that lab has now transferred an original hair sample to the FBI Laboratory for testing. We remain fully committed to this investigation."

According to the outlet, the FBI was planning to use "new technology to conduct advanced analysis on the DNA sample" in order to see whether it might provide information about Nancy's alleged kidnappers.

Sheriff Nanos had previously revealed in March that authorities had collected a number of DNA samples from Nancy's home, but that authorities were struggling to extract individual profiles from that evidence.

"It’s a challenge because we know we have DNA, but now we have to deal with that mixture and how we’re going to separate it," he said.

Sheriff Nanos has previously admitted that authorities were still trying to separate out cross-contaminated DNA discovered inside Nancy's home, revealing that investigators had run into some "challenges" in their examination of the evidence.

"We listen to our lab, and our lab tells us that there’s challenges with it, and we understand those challenges," he told NBC News.

"But our lab also knows that the technology is moving so fast and in such a frenzy that they think some of this stuff will resolve itself just in a matter of weeks, months or maybe a year, to allow them to do better with, say, a mixture of that kind of thing."

At the time, Nanos also noted that previous DNA samples that had been submitted to the Combined DNA Index System (CODIS), a database used by the FBI to track convicted criminals, have not resulted in a match, but that the additional evidence would be analyzed when they were "sorted out."

“We believe that we may have some DNA there that may be our suspect, but we won’t know that until that DNA is separated, sorted out, maybe admitted to CODIS, maybe through genetic genealogy,” Nanos added.

No other information about that DNA investigation has yet been shared; however, one former FBI special agent shed some light into the painstaking process involved in analyzing the evidence, noting that the agency will be taking its time to ensure that no mistakes are made.

"[It] takes far longer than television crime dramas would have people believe," retired agent Jason Pack told CBS News. "That kind of work is slow because it has to be right."

Pack added that, while 100 days may "feel like forever" to Nancy's family, it is still relatively early in a case of this magnitude.

Another former FBI agent, Lance Leising, also told the outlet that there are specific kinds of DNA that will be considered "high priority" by investigators, explaining: "An item containing DNA such as a strand of hair found somewhere in a house is one thing, but a strand of hair near the victim's last known location, such as in her bed, would be a high priority for the FBI."

When questioned by CBS News about the kind of DNA evidence the FBI is currently looking at, Sheriff Nanos declined to give any specifics, stating: "It would be highly inappropriate of me to speak to the evidence. We have to keep the integrity of this case.

"If we make an arrest, that individual has the right to a fair trial, [so] I can't sit here and address all of that. We are working hard with all of our partners to resolve this case, and we will."

The statement comes two days after Savannah, 54, issued a new plea to the public for their help in finding her mom, while sharing a touching series of images and videos of the 84-year-old in and around her home, in honor of Mother's Day.

The photos and videos capture Nancy spending time with her family, including children Savannah, Annie, and Cameron, as well as her grandchildren.

"Mother, daughter, sister, Nonie—we miss you with every breath. We will never stop looking for you. We will never be at peace until we find you," Savannah wrote in the caption of the video.

The "Today" host went on to issue a fresh plea to members of the public, asking for their help in finding her mother, calling attention to the fact that the $1 million her family promised to anyone who provides information about Nancy's whereabouts is still available.

"We need help. Someone knows something that can make the difference," she continued. "Call 1800CALLFBI. You can be anonymous and the reward remains available.

"Please keep praying. Bring her home."

Photos and videos included in the post capture Nancy over a period of many years, including some taken when Savannah and her siblings were still children, while others show the grandmother building gingerbread houses with her grandkids or spending time with her own siblings.

What is the full timeline of Nancy Guthrie's disappearance?

Nanos noted during a media briefing on Feb. 5 that, while times are approximate, his team has pieced together several pieces of evidence that indicate Nancy's movements—and the timeline of her apparent abduction.

Nancy was reported missing at around 12 p.m. local time on Feb. 1, around 14 hours after she was dropped off at the property following a family dinner. When she failed to turn up at her usual church gathering on Sunday, her friends alerted her family, who found her home was empty.

SATURDAY, JAN. 31

5:32 p.m. Nancy travels to Annie's house in an Uber for "dinner and playing games with the family."

9:48 p.m. A garage door at Nancy's house opens when she was dropped off at the property by her daughter.

9:50 p.m. The garage door closes, indicating that Nancy was inside the home.

SUNDAY, FEB. 1

1:47 a.m. Nancy's doorbell security camera is disconnected.

2:12 a.m. Movement is detected on a security camera at the home. No footage of this is currently available.

2:28 a.m. Nancy's pacemaker app indicates that the device has been disconnected from her phone.

11:00 a.m. Nancy fails to arrive at the home of a friend, where she had been due to watch a church service livestream.

11:56 a.m. Nancy's family travels to her home to check on her and finds the property empty.

12:03 p.m. The family calls 911 to report Nancy missing.

12:14 p.m. Police officers arrive at Nancy's home.