Nancy Guthrie Update: Investigators Admit Missing Mom's DNA May Be 'Unusable'

Nancy Guthrie has now been missing for nearly four weeks since investigators theorized that she was possibly abducted from her home in Tucson, Arizona, on Feb. 1. Authorities say a key line of inquiry hinges on whether DNA recovered inside the house can be used as evidence. Meanwhile, Savannah Guthrie has since announced that their family is offering up to $1 million for information that could lead them to their mum.

What is newly troubling is not a lack of effort, but the possibility that one of the most straightforward forensic routes may simply fail on a technicality. Sources familiar with the investigation told CBS News the DNA sample is 'low-level,' and the sheriff's office says a contracted lab in Florida is still analysing it and has not determined whether it can produce a viable result. What remains unchanged is the central void, with no suspect named and no arrest made.

For anyone trying to keep the strands straight, the picture currently looks like this. Investigators have DNA from inside the home that may not yield a usable profile, DNA from gloves found about two miles away that produced no match in the FBI's CODIS system, and doorbell footage of a masked person with a backpack approaching the home on the night Nancy Guthrie was taken.

Nancy Guthrie DNA Hit A Harsh Laboratory Reality

It is tempting, in a case like this, to treat DNA as a switch you flick. Either it matches or it does not. Real life is messier, and this week's update is a reminder of how thin the margins can be.

The sheriff's office has said its contracted lab in Florida is still working through the evidence and has not determined whether the DNA recovered from inside Nancy Guthrie's home can produce a viable result. That careful phrasing matters, because it leaves room for both outcomes, a usable profile that opens doors or an inconclusive technical dead end that keeps them shut.

Straight Arrow News, citing sources familiar with the investigation who spoke to CBS News, said the sample is considered 'low-level,' which suggests there may not be enough material to generate a reliable match in federal or private databases. If that is right, it narrows one of the clearest paths to identifying whoever took her. None of this is confirmed publicly beyond what officials have said about the lab work continuing, so the sharper claims should be taken with a grain of salt until investigators put them on the record.

The uncertainty around the in home DNA lands on top of an earlier disappointment. Investigators have already confirmed that DNA recovered from gloves found about two miles from Guthrie's home did not match any profiles in the FBI's Combined DNA Index System, known as CODIS. Detectives are continuing to process additional evidence collected during searches in the Catalina Foothills area.

No suspect has been named. Sheriff Chris Nanos said last week that Guthrie's three adult children and their spouses have been cleared, which reads like an attempt to shut down the kind of speculation that can poison a case and torment a family at the same time.

Nancy Guthrie Case Turns To Genetic Genealogy

With no CODIS match from the gloves, authorities are turning to genetic genealogy, comparing unidentified DNA to publicly available genealogy databases in search of relatives who could point them to a suspect. The method has helped identify the Golden State Killer after decades without a break, a fact that gets cited often because it is the rare example everyone recognises.

It is also not a magic trick. Use of those databases depends on voluntary participation, and Straight Arrow News notes that companies hosting the platforms allow users to opt in to law enforcement searches. Investigators have not said whether that process has produced any leads.

Alongside the forensic grind, the Guthrie family is trying to force the world to keep looking. Savannah Guthrie said in a video message that it had been 'Day 24 since our mom was taken in the dark of night from her bed, and every hour and minute and second and every long night has been agony since then' and added, 'We need to know where she is. We need her to come home.'

The family's offer, up to $1 million for information that leads to Nancy Guthrie's recovery, sits beside a separate FBI reward of $100,000 for information that results in an arrest and conviction. It is a blunt instrument, money in exchange for a crack in someone's silence, but families reach for blunt instruments when the sharp ones are not cutting.

Investigators believe Nancy Guthrie was abducted from her home on 1 February. Doorbell camera footage released earlier this month shows a masked individual wearing a backpack approaching the residence that night, and authorities later described the person as a suspect but have not identified or arrested anyone. The investigation remains active.