Authorities in Pima County, working alongside the FBI, briefly took an individual into custody and later released them after questioning related to the disappearance of Nancy Guthrie, the 84-year-old mother of “TODAY” co-anchor Savannah Guthrie, according to a law enforcement official familiar with the case who spoke with ABC News.

The person was stopped and detained during an encounter south of Tucson, and investigators conducted a search tied to that individual as part of the ongoing inquiry. In a post shared on social media, the Pima County Sheriff’s Department confirmed that deputies had “detained a subject during a traffic stop.”  Officials said the sheriff’s department, with support from the FBI’s Evidence Response Team, executed a court-approved search at a property in Rio Rico, Arizona, roughly 60 miles south of Tucson. The Pima County Sheriff’s Department said hours later it had completed the search of the property, adding that the investigation was ongoing.

Earlier on Tuesday, federal authorities released newly recovered surveillance images and videos tied to the disappearance of Nancy Guthrie as investigators intensify efforts to locate her more than a week after she vanished from her Arizona home.

The FBI and the Pima County Sheriff’s Department shared four black-and-white images and several short video clips showing a masked individual outside Guthrie’s residence near Tucson in the early hours of Feb. 1, the morning she was reported missing. The person is seen wearing gloves, a face covering, khaki pants, sneakers and a backpack, and appears to deliberately interfere with the home’s doorbell camera. In one clip, the individual approaches the front door with their head lowered; in another, they face the camera with a flashlight held in their mouth before obscuring the lens with what authorities believe to be prairie brush.

FBI Director Kash Patel said the footage depicts an “armed individual,” noting that a possible firearm can be seen holstered at the front of the person’s belt. According to investigators, the subject’s actions suggest prior knowledge of the camera’s location. No nearby vehicle is visible in the footage, though law enforcement believes one could have been parked elsewhere on the street. Patel explained that the video had initially been unavailable due to technical issues, including the removal or disruption of recording devices. The material was ultimately recovered from residual backend data with help from private-sector partners.

Authorities believe Nancy Guthrie was taken against her will. She had been dropped off at her house the night of Jan. 31 and was reported missing around noon the following day.  Pima County Sheriff Chris Nanos said the doorbell camera stopped functioning around 1:47 a.m. on Feb. 1. Additional data showed motion detection shortly afterward, and Nancy Guthrie’s pacemaker app disconnected from her phone at 2:28 a.m. Her phone and critical medication were later found inside the home.

Despite the release of the images, officials stressed that no suspects or persons of interest have been identified. The individual seen in the footage is currently described only as a subject investigators are trying to identify. Savannah Guthrie has repeatedly appealed to the public for assistance, sharing the FBI’s images and videos across social media. In one post, she wrote, “Someone out there recognizes this person. We believe she is still out there. Bring her home.” In another emotional video message, she urged people nationwide to report anything unusual, saying, “We are at an hour of desperation, and we need your help.”

According to reports, a note sent to a local television station demanded $6 million and included a threat against Nancy Guthrie’s life. The FBI, however, has said it is “not aware of any continued communication between the Guthrie family and suspected kidnappers,” and confirmed that the latest deadline tied to a bitcoin ransom has passed. Savannah Guthrie and her siblings have publicly stated they are willing to pay for their mother’s safe return. In a video alongside her brother and sister over the weekend, Savannah Guthrie addressed those responsible directly, pleading, “We beg you now to return our mother to us so that we can celebrate with her. This is the only way we will have peace. This is very valuable to us, and we will pay.”

The FBI is also offering a $50,000 reward for information leading to Nancy Guthrie’s recovery or a conviction related to her disappearance. Agents from across the country have been deployed to support the search, and a 24-hour command post remains active in Tucson. Anyone with information is urged to contact the FBI at 1-800-CALL-FBI (1-800-225-5324) or the Pima County Sheriff’s Department at 520-351-4900.

Editorial credit: Kathy Hutchins / Shutterstock.com