TUCSON, Ariz. — It's been 100 days since 84-year-old Nancy Guthrie's suspected abduction from her Tucson bedroom, and authorities say they have "nothing new" — as outside volunteer groups push to join the search.

Guthrie vanished from her home in the Catalina Foothills, an upscale suburb north of Tucson, in the early hours of Feb. 1, according to authorities. There have been no signs of her since. There are no publicly identified suspects, beyond a masked man who appeared on her front steps on doorbell video.

"We just want to help, and we just want to find Nancy Guthrie," said Josh Gill, an organizer at the Louisiana-based nonprofit United Cajun Navy, which volunteers for search and rescue operations around the country. "That's it."

UCN has participated in several other successful searches recently, including one that found missing Louisiana 14-year-old state police, who found her alive, Gill said.

"They found her and reported it," he told Fox News Digital, adding that's not the first time someone saw a UCN post about a case before calling in a tip that helped crack it.

Another group, Madres Buscadoras de Sonora (Searching Mothers of Sonora), has also asked for permission to help.

Fox News Digital asked the Pima County Sheriff's Department for details about air and ground searches last week; however, they declined to discuss anything beyond what investigators shared with the public back on Feb. 2.

"We had a map in the initial press conference on the screens for the initial search," a spokesperson said. "I've been advised that we do not have any additional information to provide."

That map appears to show the search heavily focused on Guthrie's immediate neighborhood. The colored lines represent ground searches. Two rings showed the general area of ground covered by helicopter and plane.

On Saturday, Pima County Sheriff Chris Nanos told Fox News Digital that his investigators are getting closer to solving the case. He did not elaborate, however.

The most recent publicly known development is that a private lab in Florida that received DNA evidence from inside Guthrie's home back in February had transferred the sample to the FBI for more advanced analysis after 11 weeks.

The case entered its 14th week Sunday.

Speaking with Fox News' Jonathan Hunt Monday, Nanos said investigators were still working with the labs and following up on leads.

"There is really nothing new," he said.

Gill's group previously sent a 41-page proposal to the sheriff's department, seeking an official blessing from authorities before sending volunteers with K9s, drones and medical equipment. However, he told Fox News Digital that despite offering to revise the plan and a Change.org petition asking the sheriff to invite them in, the group has received "zero response."

"At this point, I can't imagine saying no to anyone offering help," said Bob Krygier, a retired Pima County Sheriff's Department lieutenant who has been following the case. "Those are just extra feet on the ground that I don't have to pay, quite honestly."

Jason Pack, a retired FBI supervisory agent, said task force investigators are likely still making progress behind the scenes.

"If investigators are still reviewing evidence, revisiting timelines and pushing forensic analysis forward, then the case is still moving, even if most of that movement happens far from television cameras and social media speculation," he told Fox News Digital. "And sometimes the most important breakthroughs happen quietly long before the public ever hears a word about them."

There's a combined reward of more than $1.2 million that remains unclaimed. The family is urging anyone with information to dial 1-800-CALL-FBI.

To remain anonymous, contact Tucson's 88-Crime tip line at (520) 882-7463.