TUCSON, Ariz. — A person has been detained for questioning in the disappearance of Nancy Guthrie, according to two people familiar with the matter.

The people said the person was detained in an area south of Tucson on Tuesday night. They did not immediately provide additional details, and it wasn’t clear if the person being questioned is the person captured on surveillance video from outside Guthrie’s house released earlier Tuesday.

The people were not authorized to discuss details of an ongoing investigation and spoke on condition of anonymity.

The FBI released surveillance images of a masked person with a handgun holster outside Guthrie’s front door the night she vanished, offering the first major break in a case that has gripped the nation for more than a week.

The person wearing a backpack and a ski mask can be seen in one of the videos tilting their head down and away from a doorbell camera while nearing an archway at the home of the mother of “Today” show host Savannah Guthrie.

The footage shows the person holding a flashlight in their mouth and trying to cover the camera with a gloved hand and part of a plant ripped from Nancy Guthrie’s yard.

The videos — less than a combined minute in length — gave investigators and the public their first glimpse of who was outside Nancy Guthrie’s home just outside Tucson, but the images did not show what happened to her or help determine whether the 84-year-old is still alive.

FBI Director Kash Patel said the “armed individual” appeared to “have tampered with the camera.” It was not entirely clear whether there was a gun in the holster.

The videos were pulled from data on “back-end systems” after investigators spent days trying to find lost, corrupted or inaccessible images, Patel said.

“This will get the phone ringing for lots of potential leads,” said former FBI agent Katherine Schweit. “Even when you have a person who appears to be completely covered, they’re really not. You can see their girth, the shape of their face, potentially their eyes or mouth.”

By Tuesday afternoon, authorities were back near Nancy Guthrie’s neighborhood, using vehicles to block her driveway. A few miles away, law enforcement was going door-to-door in the area where daughter Annie Guthrie lives, talking with neighbors as well as walking through a drainage area and examining the inside of a culvert with a flashlight.

Investigators have said for more than a week that they believe Nancy Guthrie was taken against her will. She was last seen at home Jan. 31 and reported missing the next day. DNA tests showed blood on her porch was hers, authorities said.

She has high blood pressure and issues with mobility and her heart, and she needs daily medication, officials have said.

Until now, authorities have released few details, leaving it unclear if ransom notes demanding money with deadlines already passed were authentic, and whether the Guthrie family has had any contact with whoever took Nancy Guthrie.

Savannah Guthrie posted the new surveillance images on social media Tuesday, saying the family believes Nancy Guthrie is still alive and offering phone numbers for the FBI and county sheriff. Within minutes, the post had thousands of comments.

Investigators had hoped cameras would turn up evidence right away about how Nancy Guthrie disappeared from her home in an secluded neighborhood.

But the doorbell camera was disconnected early on Feb. 1. While software recorded movement at the home minutes later, Nancy Guthrie did not have an active subscription, so Pima County Sheriff Chris Nanos had initially said none of the footage could be recovered. Officials continued working to get the footage.

Heartbreaking messages by Savannah Guthrie and her family shifted from hopeful to bleak as they made pleas for whoever took Nancy Guthrie. In a video just ahead of a purported ransom deadline Monday, Savannah Guthrie appeared alone and spoke directly to the public.

“We are at an hour of desperation,” she said. “We need your help.”