As the Nancy Guthrie case is reportedly bogged down, investigators released the ransom notes, which they previously put under wraps.

In reaction to the notes, investigators observed a development in the investigation.

According to ABC, the Pima County Sheriff's Department saw a slight increase in leads; however, they did not lead to a breakthrough.

"Investigators have seen a slight increase in tips since the two ransom notes were released," the Sheriff's Department said, noting that "all tips have been followed up on."

While, the two notes that were released include allegedly shocking details related to Nancy.

The first one read, which was sent on Feb. 2, "We have your mother Nancy. She is safe but scared."

In return, the presumed captors demanded millions of dollars in Bitcoin and threatened to "kill" her if the amount was not given.

The second note, even more shocking than the previous, and sent days later, alleged Nancy had died and was "buried in nature."

"We did not fully grasp the seriousness of her physical condition," the note alleged.

"We never intended to hurt her, that was not our intention. She perished shortly after she was taken."

The disturbing message also included an apology by the alleged kidnappers, "Nothing you could have done could have changed the outcome. We want your family to know this and hope you all can find peace."

Meanwhile, investigators are yet to arrest a suspect in Nancy's case, who has been missing from her home near Tucson, Arizona, since Feb. 1.