Law enforcement are preparing to turn Nancy Guthrie’s Tucson-area home back over to her family, sources say, as the search for her is in its fourth week. The 84-year-old mother of “TODAY” show co-anchor Savannah Guthrie was reported missing on Feb. 1. For weeks her home has been the cent er of a flurry of law enforcement activity — including the recovery of DNA evidence. Activity seen Wednesday is related to efforts to turn the home back over the Guthrie family, two federal law enforcement sources told NBC News. Officials acknowledged that law enforcement no longer see the need to seal the premises as a crime scene or restrict the family from entering. It’s not immediately clear what the FBI or the Pima County Sheriff’s Department was doing inside the home Wednesday, but it did not appear that they were engaged in activities outside the home that were seen on prior visits that included testing or retracing their steps. There’s been more than 23,000 calls to the FBI tip line since Guthrie was taken, and 750 of those calls came in the first 12 hours after Savannah Guthrie posted on Instagram Tuesday offering a $1 million reward, a senior official familiar with the investigation told NBC News. Guthrie was last seen on Jan. 31 around 9:45 p.m. following dinner at her daughter Annie’s home, according to Pima County Sheriff Chris Nanos. She was reported missing the following day when she did not show up to watch a virtual church service with friends. Authorities have not identified a suspect in her possible abduction. Arizona Feb 24 ‘TODAY' co-anchor Savannah Guthrie says family is offering $1M reward for the recovery of her mother Arizona Feb 23 One photo of man on Nancy Guthrie's porch may be from an earlier date, before her disappearance Arizona Feb 23 What could come next in the investigation into Nancy Guthrie's disappearance The FBI on Feb. 10 released photos taken from Guthrie’s Google Nest camera that showed a masked, armed man later described as a suspect outside her home the morning she vanished. In that clip, the person appeared to tamper with the camera. Most of those images showed a masked individual with a backpack. But one did not, showing the person in dark clothing with a mask and gloves without a backpack. On Monday two law enforcement sources familiar with the investigation said that the image without the backpack was captured earlier, not the morning of her disappearance. The FBI declined to comment on possible dates tied to the image. The Pima County Sheriff’s Department said Monday that there was no date or timestamp associated with that image and any suggestion that it was taken on a different day is “purely speculative.” Nanos said officials believe the majority of those images were from Feb. 1 only because they show the doorbell being disconnected. The Pima County Sheriff’s Department and the FBI continue to actively pursue “all viable leads,” the department said Tuesday evening. DNA evidence has been collected from Guthrie’s home and related search locations and has been submitted for forensic analysis, the sheriff’s department has said. But testing thus far has yielded no results. Nanos has said mixed DNA was recovered from her home, meaning a DNA sample that contains genetic information from at least two people, but there have been challenges with those samples. ...read more read less