‘No alternative’: Experts express concerns about Nancy Guthrie investigation as FBI uses ‘new’ techniques to solve case

Now, FBI agents are using advanced forensic techniques to analyze the evidence in hopes of solving the case.

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“When a law enforcement agency of this size starts outsourcing old samples to multiple labs, that tells you that the original leads they were pursuing have disappeared,” the professor said. “Honestly, they’re not finding new evidence, they’re just trying to squeeze more evidence out of what’s already there. They’re clearly running out of options.”

The new DNA is a mixed sample, meaning it contains genetic makeup from multiple people.

Pima County Sheriff Chris Nanos Acknowledging the new evidence poses significant challenges for his department. He warned that results could take “weeks, months or even a year.”

The professor emphasized that mixing DNA samples does pose a challenge and can be very frustrating.

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“You can have many contributors in a sample and spend a lot of resources, both time and money, trying to isolate a usable sample profile,” he said. “The new technology the FBI has brought in tells me they believe the sample contains the suspect’s DNA; they just haven’t been able to get a clean sample out yet.”

Nanos previously said the Sheriff’s Department was still working with the FBI, labs and forensic examiners across the country and “we still have thousands (hours) of video footage to sort through.”