Federal investigators have concluded that DNA testing on hair found at the Arizona residence of missing 84-year-old Nancy Guthrie does not identify any suspects, officials said Friday. Guthrie, mother of NBC News personality Savannah Guthrie, was last seen at her Tucson-area home on January 31 and formally reported missing the following day.

Pima County Sheriff Chris Nanos confirmed that the FBI-led investigation has yielded no breakthroughs from the hair evidence collected at the scene. “All hair had been resolved and it does not point to a suspect,” authorities indicated, noting that hair samples typically offer limited DNA unless roots or skin cells are present. The sheriff expressed continued optimism that ongoing analysis of other DNA and video evidence could help solve the case, highlighting the volume of material investigators are still reviewing.

Among the key pieces of evidence publicly released is video from the home’s doorbell camera showing a masked, armed individual wearing gloves near Guthrie’s front door around the time she likely was abducted. Sheriff Nanos said it was not unexpected that the hair evidence did not yield a definitive lead in light of forensic limitations.

In the weeks since Guthrie’s disappearance, law enforcement detained several individuals in connection with the investigation. One man, Carlos Palazuelos, who was held for several hours before being released without charge, has now filed a formal notice of claim against the Pima County Sheriff’s Department, Sheriff Nanos, and Detective Earl Gieron. Palazuelos alleges wrongful targeting, excessive force during his arrest on February 10, and significant damage to his family’s home during the subsequent search.

Palazuelos’ legal complaint contends that his arrest was publicly executed in a manner intended to humiliate and implicate him falsely in Guthrie’s disappearance, which he describes as an effort by law enforcement to divert criticism and advance Sheriff Nanos’ public image. He is pursuing $2.5 million in claims including assault, false arrest, negligence, defamation, and false imprisonment.

Additionally, two other plaintiffs have joined with related claims. Daniel Maddox seeks $500,000, citing being handcuffed and held under armed guard during the search, while Josefina Maddox, owner of the searched property and Palazuelos’ mother, is seeking $250,000 for property damage, including a broken door frame and damaged ceiling tiles.

Nancy Guthrie’s family has repeatedly appealed for information on her whereabouts. In a recent video message, Savannah Guthrie described the ongoing ordeal as a nightmare and pleaded with anyone possessing information to come forward. Nancy Guthrie, who suffers from limited mobility and a heart condition, remains missing as investigators continue their search.