Nancy Guthrie Case: CODIS No-Match Result Pushes FBI Toward Forensic Genealogy as Hidden DNA Clue May Identify the Suspect

Investigators have confirmed that the DNA found on a glove discovered two miles from the home of Nancy Guthrie did not match any of the 19 million profiles stored in CODIS, the national criminal DNA database used by federal, state, and local law enforcement agencies. The no-hit result signals a pivotal shift in the direction of the investigation — and it places the case on a path previously used to capture one of America’s most notorious criminals.

With CODIS yielding no match, the FBI has now turned to forensic genealogy, the highly specialized investigative method used to identify the Golden State Killer after four decades. Through this method, genealogists construct an offender’s extended family tree by comparing crime-scene DNA with voluntarily uploaded DNA profiles in public ancestry databases.

In the Guthrie case, investigators say the suspect made one critical mistake:
He left behind viable DNA inside a glove discarded along a desert access road.

While CODIS could not identify him, the genetic material is intact — and that means his family can identify him instead.

A No-Match That Changes Everything

The CODIS result is both alarming and informative. A no-hit result generally means one of the following:

The suspect has never been arrested for a qualifying crime.

He has never submitted a DNA sample to any law-enforcement database.

He has no known criminal record that required DNA collection.

He may be from another state or another country with no cross-linked database.

Authorities say this places the suspect in a category of individuals who are “statistically harder to identify” — but far from impossible to track.

A senior forensic analyst familiar with the case explained:

“CODIS is powerful, but it only catches people already in the system. Forensic genealogy catches everyone else.”

The Glove: The One Mistake That May Break the Case

The glove — now central to the investigation — was recovered near a wash road approximately two miles from Guthrie’s neighborhood. Search teams initially flagged it due to its condition, location, and proximity to the ongoing search perimeter.

Forensic testing confirmed:

– the glove was recently discarded
– it contained a full, viable male DNA profile
– the profile does not match Guthrie or anyone in her family
– and crucially, it is consistent with DNA found inside her home

This connection has reoriented the investigation, narrowing focus from broad leads to a single unknown male whose identity now hinges on genetic relatives.

Why CODIS Returned No Match

When DNA samples are uploaded into CODIS, they undergo comparison against:

– convicted offender databases
– arrestee databases
– forensic casework files
– parolee and probation databases

The Guthrie suspect’s DNA — now tested multiple times — matched none of them.

Investigators emphasize that this does not diminish the strength of the evidence. Instead, it suggests the individual has successfully avoided the criminal justice system throughout his life.

One retired investigator noted:

“The most dangerous offender is often the one with no record. They leave no trail until the moment they make a mistake.”

FBI Genealogy Team Activated

With CODIS exhausted, the FBI’s forensic genealogy unit has begun building the suspect’s family tree — a process involving:

– uploading crime-scene DNA to authorized genealogy databases
– identifying individuals who share large segments of genetic material
– locating second-, third-, or fourth-cousins
– mapping shared grandparents or great-grandparents
– eliminating unrelated branches
– narrowing the tree to living male descendants
– cross-checking each with age, geography, and movement patterns

In many cases, investigators never need a close relative.
A third cousin can be enough.

The suspect’s DNA contains markers that bind him genetically to distant relatives who have voluntarily submitted their DNA online — often through ancestry sites that allow law-enforcement access for violent-crime investigations.

A Proven Method: The Golden State Killer Example

This is the same forensic strategy that identified Joseph James DeAngelo — the Golden State Killer — in 2018. DeAngelo had eluded police for 40 years. CODIS failed. No fingerprints matched. No suspect sketches held up.

But one distant relative uploaded DNA to a public genealogy site.

And within weeks, detectives had a name.

The Guthrie investigation now follows this same trajectory, with analysts already working through thousands of genetic relationships and historic family branches.

A federal agent described the process this way:

“DNA doesn’t lie. Even when a suspect hides his identity, his relatives don’t.”

Why the Glove Matters More Than Any Other Clue

The glove’s location suggests the suspect may have:

– exited the area on foot
– staged part of the crime away from the residence
– attempted to discard items while fleeing
– panicked or acted impulsively

Most importantly, it indicates the suspect shed genetic material during the commission of the offense.

Even if he attempted to wipe the scene clean, the glove betrays him.

Genetic genealogists can build a family tree backward from:

– DNA fragments
– familial matches
– shared chromosome segments
– long blocks of identical DNA
– ancestral migration patterns

Each piece eliminates thousands of potential suspects until only one remains.

Investigators: “It’s Not a Question of IF — It’s WHEN”

Multiple sources familiar with the investigation say that once a viable family tree is constructed, detectives will begin silently interviewing relatives, reviewing birth records, and cross-checking:

– age
– gender
– geographic history
– employment
– criminal or behavioral background
– digital footprints
– vehicle ownership
– proximity to Guthrie’s neighborhood

The final step is a surreptitious DNA collection — from a discarded cup, a cigarette butt, or a public item — to match the suspect with certainty.

This process often takes weeks to months, but rarely more.

A federal investigator close to the case stated:

“When genealogy works, it’s unstoppable. This guy’s DNA already knows who he is — even if no one else does.”

A Case That Has Gripped the Country

The disappearance of Nancy Guthrie — with blood found on her porch, a missing doorbell camera, a masked man on video, and unknown male DNA inside the home — has become one of the most closely watched missing-person cases in Arizona in years.

The no-match CODIS result, initially discouraging, has now shifted into what investigators believe may be the strongest lead yet.

Forensic genealogy is designed specifically for cases like this:
a serious, violent crime committed by someone outside the criminal system, who nevertheless left a biological trail.

The Suspect’s World Is Shrinking

Genealogical triangulation is unforgiving. Once distant relatives are identified, investigators can pinpoint:

– which family line the suspect belongs to
– which branch matches the genetic markers
– which modern descendants fit the profile
– who was living or traveling near Guthrie’s area
– who has the physical characteristics seen in surveillance footage

The suspect may be unknown today.
But soon he will be one of dozens, then a handful, then one.

That is how the Golden State Killer was caught.
And that is how countless cold cases have been solved since.

Conclusion: The Clock Is Ticking — Against Him

The CODIS no-match result is not the end of the investigation — it is the beginning of the most precise, advanced stage. The glove he left behind is enough. And the DNA inside that glove will, investigators say, name him.

Not through fingerprints.
Not through eyewitnesses.
Not through criminal records.

But through his own bloodline.

In the words of one forensic genealogist:

“He left his identity at the scene. The rest is just math.”