The investigation into the disappearance of Nancy Guthrie has entered a renewed phase of public attention after authorities released two purported ransom notes connected to the case, a move investigators say has already generated an increase in new tips.

The 84-year-old mother of “TODAY” co-anchor Savannah Guthrie disappeared from her home in Arizona’s Catalina Foothills after she was last seen on the evening of January 31. When she failed to arrive at church the following morning, family members reported her missing. Authorities have said they believe she was taken from her home against her will.

Six months later, investigators are still working to determine exactly what happened.

On July 31, the Pima County Sheriff’s Department publicly released two redacted notes that had been sent to Tucson television station KOLD shortly after Guthrie disappeared. Investigators hoped that exposing the language, phrasing and writing patterns contained in the messages could lead someone to recognize the person behind them.

That strategy may be producing new leads.

The sheriff’s department said investigators assigned to the Nancy Guthrie Task Force have seen a “slight increase” in tips since the notes became public and that every tip received has been followed up.

The first message, sent on February 2, claimed Nancy was alive and being held for ransom. Its writer demanded $4 million in Bitcoin and threatened to increase the amount to $6 million if an initial deadline passed.

The second communication, sent several days later on February 6, took a dramatically different tone. Instead of demanding money, its writer claimed Nancy had died shortly after being taken and suggested that an existing health problem may have contributed to her death. The message also claimed that she had subsequently been buried somewhere outdoors.

Those claims should not be confused with an official determination of what happened to Guthrie. Authorities have not announced that they have located her remains, and she remains missing.

The release of the notes appears intended to provide investigators with something beyond their literal claims: the writer’s language.

Authorities have said the communications contain patterns in syntax, vocabulary and phrasing that could potentially be recognizable to someone familiar with the author. Investigators are therefore asking members of the public to consider not only whether they know something about Guthrie’s disappearance, but whether the writing itself reminds them of someone they know.

The notes have attracted additional scrutiny because certain details could potentially indicate knowledge of the crime scene. Former FBI personnel interviewed by media outlets have pointed to references involving items at Guthrie’s home as potentially significant, although investigators have not publicly established who wrote the messages or definitively explained how the author obtained that information.

The ransom notes are only one part of a much larger investigation.

Since Guthrie vanished, the Pima County Sheriff’s Department and FBI have pursued leads and examined evidence connected to her home and surrounding area. Authorities have also released surveillance footage showing a person believed to be connected to her disappearance approaching her residence.

Despite months of searching, no publicly identified suspect has been charged in Guthrie’s disappearance.

For Savannah Guthrie and her family, the passage of six months has brought no resolution.

Marking the six-month point, Savannah described a family still consumed by uncertainty and grief, saying they continue to think about their mother constantly while remaining determined to discover what happened to her.

The family has also put significant financial weight behind the search, offering a $1 million reward as investigators continue seeking information that could break the case open.

The decision to release the ransom notes therefore represents another attempt to reach someone who may possess a seemingly minor piece of information — a familiar expression, an unusual choice of words, knowledge of a person’s behavior or something witnessed around the time Guthrie disappeared.

With investigators now reporting additional tips, the key question is whether one of those new leads will finally connect the anonymous messages, the person seen near Guthrie’s home and the events of the night she vanished.

For now, authorities continue to investigate every lead while Nancy Guthrie remains missing.

Main Sources: FOX 26 Houston, ABC News, CBS News, CNN