Search for Nancy Guthrie now seeks nearby security videos from the month before she vanished

It asked for video of “anything neighbors deem out of the ordinary or important to our investigation” since the beginning of January.

Federal and local officers have been going door-to-door in Tucson neighborhoods around 84-year-old Nancy Guthrie's house while also looking for clues around her other daughter's nearby home, which she had visited just hours before disappearing.

Investigators have recovered and are analyzing several pieces of evidence, including a pair of gloves, the sheriff's department said.

Authorities on Thursday briefly put up a tent in front of Nancy Guthrie’s entryway where her blood was discovered in the early days of the investigation and where a doorbell camera captured images of a masked person the night she went missing.

Authorities have said Guthrie was taken against her will. She’s been missing since Feb. 1, and authorities say she takes several medications and there’s concern she could die without them.

While much of the nation remains engrossed by the mysterious disappearance, Savannah Guthrie on Thursday shared on Instagram a vintage home video of her mom with two children sharing pink flowers, writing "we will never give up on her. thank you for your prayers and hope.”

On Wednesday, FBI agents carrying water bottles to beat the desert heat walked among rocks and vegetation at Nancy Guthrie’s home. They also fanned out across a nearby neighborhood, knocking on doors and searching through cactuses, brush and boulders.

“They were just asking some general questions wondering if there was anything, any information we could shed on the Nancy Guthrie issue. Wanted to look around the property and after that, cameras and such," Ann Adams, a neighbor of Nancy Guthrie's oldest daughter, Annie Guthrie, told The Associated Press on Wednesday.

“They did ask specifically for the 31st of January and the morning of the first of February and then they wanted to know if we saw anything suspicious on cameras since then," Adams said.

Several hundred detectives and agents are now assigned to the investigation, which is expanding in the area, the Pima County Sheriff’s Department said.

Two investigators emerged from daughter Annie Guthrie’s home Wednesday with a paper grocery sack and a white trash bag. One, still wearing blue protective gloves, also took a stack of mail from the roadside mailbox.

Adams, the neighbor, said she was out walking her dog earlier this week when, "it started to get really busy and then I heard about them searching, looked down the street, I saw them slowly moving this way.”

Savannah Guthrie and her two siblings have indicated a willingness to pay a ransom. But it's not known whether ransom notes demanding money with deadlines that have already passed were authentic.

Associated Press writers Sejal Govindarao in Phoenix, John Seewer in Toledo, Ohio, and Ed White in Detroit contributed to this report.