Nancy Guthrie update: ‘Investigator’ questions Tommaso Cioni's actions as ‘prime suspect’ claims resurface

A self-styled investigator questioned some of Tommaso Cioni's actions amid the search for his kidnapped mother-in-law, Nancy Guthrie.

Pima County Sheriff Chris Nanos revealed that a hair sample recovered from Nancy Guthrie's Tucson home couldn't be profiled, but the investigation remains "active and ongoing" as it nears the six month mark.

NBC / Nathan Congleton/NBC via Getty I DNA testing of hair from the home of Nancy Guthrie has not led investigators closer to a suspect in her disappearance, Pima County Sheriff Chris Nanos said Thursday. Nanos told ABC News about the discouraging forensic development in the investigation into Today show host Savannah

DNA testing on a hair found in Nancy Guthrie's home returned no profile, but investigators say the sample may still prove valuable as the case continues.

Hair found in the Arizona home of Nancy Guthrie is not linked to any potential suspects in her disappearance, federal law enforcement officials said Thursday.

That leaves a mixed sample of DNA retrieved from the home as the only known piece of biological evidence in the case.

Nancy Guthrie sheriff shares update after Savannah Guthrie video plea  USA Today