Nancy Guthrie Case Update: More than four months have passed since Nancy Guthrie, the 84-year-old mother of NBC journalist Savannah Guthrie, vanished from her home in Tucson, Arizona. Investigators with the Pima County Sheriff's Office and the FBI continue to pursue leads and tips as they work to identify and arrest a suspect in the case.Amid ongoing efforts to locate Nancy, the disappearance has drawn national attention. Several theories have emerged from former detectives and investigators, who have sought to speculate on what may have happened on the night she disappeared and to better understand the individual or individuals allegedly responsible for her abduction.Nancy Guthrie disappeared on the night of January 31, 2026, and was reported missing by her family on February 1, 2026. Within days of launching the investigation, authorities said they believed she had been taken from her home against her will.Retired detective gives a fresh aspect Amid numerous theories and speculation surrounding the case, retired detective Jon Buehler said one potential breakthrough could come from tracking vehicles that were near Guthrie’s home or identifying who may have searched for her address. While speaking to NewsNation’s Brian Entin, he noted that newer vehicles often have tracking capabilities that could provide valuable investigative leads.“If somebody ever plugged her address into a Google search for a Google Maps or whatever, if they did a reverse keyword search on that because those records are maintained for a period of time, to see any random person that would have typed in her address that had a reason to do it and then you’d contact that person and find out why did you put that address,” he said.Buehler said investigators could identify and rule out people with legitimate reasons for being near the home, such as delivery drivers, while focusing on individuals who may warrant closer scrutiny. He noted that Guthrie appeared to be a low-risk victim apart from the public profile of her daughter, adding that her daughter's fame could have motivated someone who had contact with Guthrie and believed a ransom could be paid.ALSO READ: Nancy Guthrie’s kidnapper’s name hidden in thousands of tips and leads? Retired detective's ‘twofold' abduction theory can leave you shocked“Any tradespeople that maybe were doing plumbing repair or electrical repair, anybody who was delivering furniture, anything that came up where somebody could see her as a source of ransom because of the connection with Savannah and Savannah’s notoriety,” Buehler told Entin. Buehler also claimed that the suspect’s name might be hidden among the thousands of tips investigators have received. He added that he believes a single individual is responsible for the crime.FBI and Guthrie family offered rewardsThe investigation into Nancy Guthrie’s disappearance has entered its fifth month. To encourage information from the public, the FBI initially offered a $50,000 reward for information regarding Guthrie’s whereabouts before increasing it to $100,000 for tips leading to her location or to an arrest and conviction in the case. In addition, the Guthrie family pledged up to $1 million to help find her.