A major development has emerged in the mysterious disappearance of Nancy Guthrie, the 84-year-old mother of “Today” show co-host Savannah Guthrie. More than five months after she vanished, investigators are still searching for answers about what happened to her.

Now, a California man has admitted to sending fake ransom communications to Guthrie’s family while the investigation was underway. Federal prosecutors say the messages were not connected to her actual disappearance.

Derrick Callella, 42, of Hawthorne, California, pleaded guilty to two counts of harassment using a telecommunication device, according to the U.S. Attorney’s Office for the District of Arizona.

Authorities say Callella called and texted Guthrie’s family on February 4 and discussed sending bitcoin. He admitted that he already knew an earlier ransom demand had been made in connection with the disappearance.

According to prosecutors, Callella acknowledged that his communications were intended to harass the family and obtain information about the ongoing missing-person investigation. His actions added another disturbing complication to a case that had already attracted national attention.

Callella now faces serious consequences. He could receive up to two years in prison, a fine of as much as $250,000, or both. He could also face one year of supervised release after serving any prison sentence. His sentencing is scheduled for September 10.

The guilty plea comes as federal investigators reportedly reached another significant conclusion: all three ransom notes that had been linked to Nancy Guthrie’s disappearance were determined to be fake communications, according to an FBI official cited by Reuters.

That revelation eliminates what once appeared to be potentially crucial clues. Yet the biggest question remains unanswered. Despite months of searching, investigative work and public tips, authorities still have not determined where Nancy Guthrie is — leaving her disappearance surrounded by uncertainty.