Nearly four months after Nancy Guthrie was abducted from her Tucson, Arizona home, no suspect has been publicly named, but a retired Pima County Sheriff's Department detective who once cracked one of the city's most notorious serial crime sprees believes investigators already have the answer sitting somewhere in a mountain of tips they haven't finished turning over.
Robbie Mayer, the former Pima County detective who solved Tucson's "Prime Time Rapist" case in 1986, shared his assessment of the Guthrie investigation in a May 20 interview with News 4 Tucson. His comments, reported by TV Insider, offer a window into how a seasoned investigator sees the case, and why he thinks the FBI will eventually crack it, even as the public grows restless.
Guthrie, the mother of NBC Today cohost Savannah Guthrie, was last seen at her Tucson home on the evening of January 31. Investigators have accumulated tens of thousands of leads. More than $1 million in reward money is available. Detectives are still processing DNA evidence and seeking information from area residents. And yet no arrest has come.
Mayer's core claim is blunt: the suspect's name is probably already in the case file. The problem is recognizing it.
"I believe the suspect's names are in those 50,000. The question is if they can recognize it when they see it. Being in a case like this is like being in a field with rocks and what you're looking for is under one rock. You just have to keep turning."
That number, 50,000, speaks to the sheer volume of information flooding investigators. Mayer knows firsthand what it means to wade through a case like that. When he worked the "Prime Time Rapist" investigation, which tracked a man presumed responsible for breaking into Tucson homes to burglarize them and sexually assault female residents from 1983 to 1986, his team dealt with more than 4,000 leads.
The Guthrie case has generated more than ten times that volume. And as Mayer recalled from his own experience, critical information can sit unprocessed for weeks or months simply because of the queue in front of it. He pointed to the Larriva case as proof.
"One of the detectives had Larriva's name as a lead, but he hadn't gotten to it yet because he had so many leads in front of that."
Brian Larriva, the man ultimately identified as the suspect in the serial crime spree, took his own life when police surrounded his house. The case was solved, but only after years of painstaking work and a near-miss buried in a pile of tips.
The parallel Mayer is drawing is clear. Volume is both the investigation's greatest asset and its most dangerous obstacle. Every lead that comes in has to be triaged, verified, and cross-referenced. The right name can sit in a stack for months before anyone gets to it. That is not incompetence. It is the arithmetic of a high-profile case with national attention and a forensic trail that investigators are still piecing together.
The retired detective did not stop at the lead-volume problem. He offered a theory about who might be responsible, and it points away from a random crime of opportunity.
Mayer told News 4 Tucson he believes more than one person was involved in Nancy Guthrie's abduction. He speculated about a theft group that was active in Phoenix roughly two years ago and that targeted elderly people with money. The details he described suggest planning, not impulse.
"These guys came prepared not to leave hair or DNA. Look at how that guy was clothed. They turned off their cell phones."
If Mayer's read is accurate, the people responsible for Guthrie's disappearance took deliberate counter-forensic steps: covering themselves to avoid shedding biological evidence, and going dark on their phones to avoid cell-tower tracking. That kind of preparation narrows the suspect pool in one sense, it suggests experience, but it also makes the investigation harder in every practical way.
Mayer acknowledged the difficulty openly. He said the case defies the usual investigative approach of matching patterns to known criminal behavior.
"This case is so unique. Most of the time we try and find patterns. We can't in this case."
That admission matters. Pattern-matching is the bread and butter of serial-crime investigation. When a retired detective with decades of experience says the pattern isn't there, it tells you something about how unusual the circumstances are. It also raises questions about whether certain investigative angles may have been underexplored early on.
Despite the challenges, Mayer expressed confidence that the case will be solved, and he pointed to the FBI as the reason.
"This is a very high-caliber investigation, and I think the FBI is gonna crack the case."
The FBI's involvement brings resources that local agencies simply cannot match: forensic laboratories, behavioral analysis units, and the ability to run leads across state and federal databases simultaneously. For a case with 50,000 tips and counting, that kind of infrastructure is not optional. It is essential.
But federal involvement also raises a question the public has been asking for months: if the FBI is running a high-caliber investigation, why hasn't it produced a named suspect yet? Mayer's answer, that the name is in the pile but hasn't been recognized, is both reassuring and unsettling. It means the system is working as designed. It also means the system's design includes long stretches where victims' families wait and the public sees nothing.
The case has drawn intense public speculation, including scrutiny of specific individuals that former FBI agents have cautioned against. Meanwhile, the investigation has been complicated by outside interference, including anonymous claims and demands for cryptocurrency in exchange for information about Guthrie's whereabouts, developments that have added noise to an already overwhelming tip line.
For all of Mayer's experience and confidence, significant gaps remain. Investigators have not publicly confirmed which agency is leading the case. The exact nature of the DNA evidence being processed has not been disclosed. No official has confirmed or denied the abduction theory in specific terms. And the source and administration of the more than $1 million reward remain unclear from public reporting.
Mayer's theory about a Phoenix-based theft group targeting elderly residents with money is just that, a theory. He did not cite specific evidence linking such a group to Guthrie's disappearance. His speculation carries weight because of his track record, but it remains unverified.
Savannah Guthrie, who cohosts NBC's Today, has shared posts on Instagram but has not made detailed public statements about the investigation's progress. The family's silence is understandable. But it leaves the public relying on retired investigators and local news outlets for any sense of where things stand.
The broader picture is one that should trouble anyone who cares about public safety in Arizona and beyond. An elderly woman was taken from her own home. Nearly four months later, no one has been charged. The reward fund has grown past seven figures. And the best assessment from a decorated former detective is that the answer is probably already in the file, if someone can just find it.
Mayer's comparison to the "Prime Time Rapist" case is instructive in another way. That investigation took years. Larriva terrorized Tucson from 1983 to 1986 before the case was resolved. The lead that identified him sat unworked in a detective's queue. The system eventually produced the right answer, but not before real people suffered real consequences during the delay.
The Guthrie family is living in that delay right now. So is the Tucson neighborhood where an 80-year-old woman vanished from her front door. The FBI may well crack this case, as Mayer predicts. But every week that passes without a named suspect is another week where the people who did this remain free, and another week where the public's confidence in the investigation erodes a little more.
Fifty thousand leads and a million-dollar reward should be enough to solve a kidnapping. If they aren't, the question isn't whether the system failed. It's whether the system was ever built to move fast enough when it matters most.
