Investigators have been unable to produce a DNA profile from a hair sample recovered inside Nancy Guthrie’s home, according to Pima County Sheriff Chris Nanos. The result is a setback in the investigation as it approaches six months, although the sheriff said the sample could still assist detectives through other forms of examination.

Nanos said investigators initially prioritised DNA testing and, working with the FBI, sent the hair to a laboratory in California for further analysis. The sheriff confirmed that the sample existed but did not explain why a usable DNA profile could not be obtained or specify what further investigative use it may have.