DNA evidence at the centre of the search for Savannah Guthrie's mother Nancy after 100 days

The search for Nancy Guthrie, the 84-year-old mother of Today show anchor Savannah Guthrie, has reached its 100th day since she was kidnapped from her Arizona home on 1 February, with investigators continuing to analyse blood evidence and DNA recovered from the crime scene.

The investigation

Pima County Sheriff Chris Nanos told People that the key to resolving the case lies in the interpretation of DNA-based evidence. In a separate interview with 12 News, he addressed the pace of progress.

"We continue to work with our labs, whether it's on the digital end or the biological end: DNA. It moves at a snail's pace, I guess, for some. But for my investigative team, and for me, we look at this as, no, this is doing exactly what we need it to do," he said.

Despite the slow pace of developments, Nanos expressed confidence that a resolution is coming. "I believe, at some point in time, we will make an arrest in this case," he stated.

Retired FBI agent challenges investigators

A retired FBI agent has raised questions about the evidence gathered at Nancy's home. Speaking to NewsNation correspondent Brian Entin, Steven Moore cast doubt on investigators' claims that only a single hair was recovered from the scene.

Moore argued that if one hair was found, there were "probably 10 more" that had either been overlooked or not yet discovered.

Moore emphasised that much of the physical evidence in cases of this nature is invisible to the naked eye, but that forensic specialists are trained to locate such trace materials.

He also pushed back on Sheriff Nanos's suggestion that the investigation is "getting closer," highlighting the growing criticism the department has faced over the lack of major breakthroughs.

Growing public scrutiny

Public confidence in the Pima County Sheriff's Department has declined over the course of the four-month investigation, with critics raising sharp concerns about the handling of the case and the pace at which it is progressing.

Nanos finds himself at the centre of a growing controversy as pressure mounts to deliver answers to the Guthrie family and the public.