UPDATE — The Pima County Sheriff’s Department has officially confirmed: Nancy Guthrie’s pacemaker is now the single most important piece of evidence left — and investigators are working urgently with the device manufacturer to pull every possible data point and establish a timeline of her final moments.

As the search for Nancy Guthrie continues, authorities in Arizona have reached out to the manufacturer of her pacemaker in hopes the device could provide key clues about her disappearance.

In a statement shared Tuesday, Feb. 17, the Pima County Sheriff’s Department gave an update on the case. The investigation began on Feb. 1 when the 84-year-old mother of journalist Savannah Guthrie was reported missing by family, having been last seen at her Tucson, Ariz., home on Jan. 31.

Regarding the pacemaker’s role in the investigation, the department said, “Investigators are attempting to locate the device and are working with the manufacturer and other experts in the field to assist in that effort.”

The department’s comments come after law enforcement sources told CBS News they are using a “signal sniffer” to assist in the search for Nancy in an attempt to detect signals from her pacemaker.

David Kennedy, a former NSA hacker who created and provided the device to authorities, referenced helicopters flying “really low to the ground” near Nancy’s home, and noted that the distance to be able to ping a signal from Nancy’s pacemaker is “very low,” CNN reported on Monday, Feb. 16.

The Pima County Sheriff’s Department previously highlighted the significance of Nancy’s pacemaker in the investigation, revealing additional details about its role in an approximate timeline of her last known moments.

At 9:48 p.m., on Jan. 31, Nancy’s family dropped her off at home and the garage door was opened. Two minutes later, at 9:50 p.m., the garage door closed. This was the last time she was reportedly seen.

Several hours later, at 1:47 a.m., her doorbell camera was disconnected. At 2:12 a.m., the camera briefly detected a person. Then, at 2:28 a.m., Nancy’s pacemaker was disconnected from the monitoring app on her cellphone.

An approximate timeline of Nancy Guthrie’s last known moments.Pima County Sheriff Dept

Tracy Walder, a former CIA and FBI agent, told PEOPLE on Monday the signal sniffer is a “new” and “somewhat experimental” form of technology.

“I don’t know how effective it’s going to be in finding Nancy’s pacemaker because you have to be just 30 to 100 feet from the pacemaker, it’s hard to detect,” Walder said. “So a helicopter has to hover low and slow in one particular area to look for it. I don’t think that’s practical. They need to know where they are looking.”

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Authorities believe a masked and armed person seen on Nancy’s doorbell camera kidnapped her in the early morning hours of Feb. 1. The FBI’s Phoenix office later described that person as “a male, approximately 5’9” – 5’10” tall, with an average build. In the video, he is wearing a black, 25-liter ‘Ozark Trail Hiker Pack’ backpack,” per an X post.

Nancy Guthrie; suspect seen in doorbell footage at Nancy’s front door on Feb. 1.Don Arnold/WireImage; FBI Phoenix/X

While that suspect’s identity remains unknown, Pima County Sheriff Chris Nanos ruled out Nancy’s relatives as potential suspects this week.

Earlier on Tuesday, the PCSD also announced that DNA evidence left behind on gloves found about two miles from Nancy’s home did not yield any matches when law enforcement ran the profile through the national DNA database. Authorities believed the gloves were similar to those worn by the assailant.

In an Instagram video shared Sunday, Feb. 15, Savannah urged “whoever has her or knows where she is” to come forward.

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A $100,000 reward has been offered for any information leading to Nancy’s recovery or an arrest in the case.

Anyone with information about Nancy Guthrie’s disappearance is asked to please contact 1-800-CALL-FBI (1-800-225-5324) or the Pima County Sheriff’s Department 520-351-4900.