Arizona Watcher
Pima County officials say a strand of hair recovered from Nancy Guthrie’s Tucson-area home did not produce a usable DNA profile; the physical hair sample has been preserved for potential future testing.
Investigators are focused on a separate mixed DNA sample recovered inside the home that contains genetic material from multiple individuals, which officials say may include DNA from as many as four people.
At least five or six laboratories across the country, including the FBI lab in Quantico and state labs in Kansas, Florida, California and Arizona, are working on the mixed sample; investigative genetic genealogy is also being used.
Doorbell camera footage captured a masked, gloved individual at Guthrie’s front entry on Feb. 1 carrying a black backpack; detectives have not been able to confirm whether the person acted alone.
Authorities continue to seek public tips and say a combined reward now tops $1.2 million for information leading to an arrest; the Guthrie family has asked for privacy while the investigation continues.
Federal prosecutors say a California man, Derrick Callella, pleaded guilty to sending fake ransom-style messages to the Guthrie family; he is not believed to be involved in the disappearance and faces sentencing.
Investigators say they remain committed to following every lead, retaining preserved biological evidence, and that advances in DNA technology and multi-lab analysis give them hope the case can be resolved.
Pima County authorities say testing on a strand of hair recovered from Nancy Guthrie’s Tucson-area residence failed to yield a usable DNA profile. Detectives are now focused on a complex mixed DNA sample recovered inside the home, with multiple labs and investigative genealogy…