The investigation into the abduction of Nancy Guthrie, the 84-year-old mother of TV anchor Savannah Guthrie, has entered its sixth month with no identified suspects and mounting concerns among those close to the case. A cryptic second note, received by the family prior to a public appeal, indicated that Nancy Guthrie had died and was "buried with nature," altering the focus of the investigation from a recovery mission.

Nancy Guthrie disappeared from her home in Tucson, Arizona, in February, hours after having dinner with her elder daughter. A masked figure was recorded on her doorstep via doorbell video, and traces of blood were found at the scene. Her pacemaker's connected app lost connection around 2 a.m., which remains the last indication of her status. Vital medication and her phone were left behind.

While the family initially made a public plea for her safe return, they had already received a second communication from the purported kidnapper stating Nancy Guthrie had died. This information, kept secret to avoid impeding the investigation, has shifted the family's focus to a recovery mission, according to sources familiar with the case.

The FBI's working theory is that Nancy Guthrie is deceased, either killed or having died due to the lack of essential medication. Investigators believe the perpetrator may be someone known to the victim or with a legitimate reason to be in the neighborhood, rather than a stranger abduction, based on statistical analysis of similar cases. However, authorities reportedly have no clear leads on who is responsible.

Complicating the investigation are reported tensions between the FBI and local investigators. The FBI claims it was kept at arm's length in the crucial early stages, a point disputed by the local sheriff. The crime scene was reportedly secured, opened, and re-secured, a process unusual in kidnapping investigations where DNA evidence is critical.

Questions have also been raised about the forensic investigation. DNA evidence, including a hair that did not belong to Nancy Guthrie or her family, was found at the scene. The FBI has criticized the decision to send DNA samples to a private laboratory in Florida instead of the FBI's facility in Quantico, Virginia, which possesses the technology to analyze hair samples without a root bulb. Sources suggest that time was lost due to these decisions, as Quantico could have provided access to the CODIS database and forensic genealogy organizations.

Despite presidential assurances that all resources would be made available, the case remains baffling to investigators. Journalist Howard Blum noted that the ransom notes are unusual, lacking specific demands and using unconventional language, suggesting the kidnapper is an amateur who may have acted impulsively and was unprepared for the complexities of holding a vulnerable octogenarian without medication.

The family has offered a $1 million reward for information. Sources close to the investigation express hope that this reward, rather than the forensic investigation, might prompt someone to come forward with crucial details, though they acknowledge it may take time.