A new anonymous tip suggesting Nancy Guthrie's remains may be buried near the Mexico-Arizona border has pushed investigators to take a fresh look at one of the most complex missing person cases of the year as a statewide 911 outage hit Pima County.The search for Nancy Guthrie, 84-year-old mother of TODAY Show host Savannah Guthrie, has taken a fresh turn. (via REUTERS)Nancy Guthrie, the 84-year-old mother of TODAY Show host Savannah Guthrie, vanished from her Tucson home overnight between January 31 and February 1, 2026. The case triggered a multi-agency investigation involving the FBI and the Pima County Sheriff's Department. No suspect has been formally named yet.Can the case be prosecuted without a body?A new anonymous tip has suggested Nancy's remains may be buried near the Mexico-Arizona border and it is now pushing investigators to reassess the case.Authorities have not confirmed any remains, a factor experts say could significantly shape whether the case can be prosecuted as a homicide.Also Read: Nancy Guthrie update: New details on Coral Michelle Smith emerge as sheriff's office speaks outLegal and investigative experts say a no-body case is still legally viable but only if investigators can build a strong enough chain of evidence. Criminal defense attorney Michael T van der Veen told Newsweek: “Prosecutors can prove it circumstantially because judges give a jury instruction… that circumstantial evidence is just as strong or stronger than direct evidence. Through the circumstantial evidence, the prosecutor can prove the corpus delicti, or ‘body of the crime.’”He added that Nancy's age and medical condition make voluntary disappearance highly unlikely. “She was 84 years old with a pacemaker and required daily medication… the odds that she voluntarily went missing are very low,” he said.Former police officer and criminal investigation professor Daniel K Maxwell told Newsweek that in no-body cases, physical and behavioral evidence becomes even more critical. “There is a premium on any physical evidence. Direct evidence includes photos, videos, and eyewitness testimony. Indirect evidence includes fingerprints, blood, hair, fibers. Circumstantial evidence also plays a big part… including suspect behavior both prior to and after the disappearance,” he said.On assessing the new Mexico tip, Maxwell said: “Assessing the credibility of a tip includes specificity, plausibility, and consistency with the facts of the case. The more detailed and verifiable the tip, the better,” per Newsweek.Also Read: Nancy Guthrie update: Body found in Arizona pond as search for missing 84-year-old continues911 outage and latest case updatesThe Pima County Sheriff's Department issued a community alert on Sunday, June 15, warning residents of a 911 outage affecting several counties across Arizona, including the county where Nancy Guthrie's home is located.The statement, shared on X, read: "The Pima County 911 Communications Center is currently being affected by a statewide 911 network outage." The reason for the outage remains unknown.The case also attracted amateur investigators, reporters and livestreamers to Nancy Guthrie's Tucson neighborhood, leading to complaints from local residents.Three YouTubers were arrested outside Nancy's home just days before the outage. One of them, Alexander Zabel Jr, was arrested on June 11 after multiple neighbor complaints and an incident in which a sergeant was knocked to the ground.He faces charges of resisting arrest and public nuisance, per Newsweek. Authorities stressed these arrests are not connected to Nancy's disappearance.