Nancy Guthrie Case: Unverified Forensics Claim About Tommaso Cioni Circulates as Family Remains Cleared

A new unverified social-media claim about Tommaso Cioni has brought renewed online attention to the Nancy Guthrie investigation, although there is no independently verified evidence in the material reviewed for this article that Cioni taught a standalone forensics or Crime Scene Investigation course.

Cioni, who is married to Nancy Guthrie's daughter Annie, has been identified in public reporting as a science and AP Biology teacher at BASIS Oro Valley in Arizona. A 2021 science-fair record also identifies Cioni as a teacher at the school.

Pima County Sheriff Chris Nanos has repeatedly said that the Guthrie family, including siblings and their spouses, are not suspects in Nancy's disappearance. In February, Nanos said the family had been cleared as possible suspects and described them as victims. In a later interview, he again said the family was not and had not been considered suspects.

Nancy Guthrie, 84, was reported missing on February 1 after she was last seen at her home in the Catalina Foothills near Tucson. Investigators have said they believe she was taken from the property against her will.

Cioni was reportedly the last known person to see Nancy. He and Annie had dinner with her on 31 January before Cioni drove her home at about 9:50 p.m., according to reporting on the case.

Unverified Claim Says Tommaso Cioni Taught Forensics

The latest social-media claim appeared on X and says Cioni taught Crime Scene Investigation techniques as part of his AP Biology class at BASIS Oro Valley.

The post alleges that the school's website showed Cioni teaching CSI techniques and says the class involved forensics, crime scenes and evidence. It then attempts to connect that claim with reports about the condition of Nancy's home after her disappearance.

The post also refers to a reported description of the interior of the home as 'immaculate' and alleges there were 'no signs of an assault'. It does not provide independently verifiable evidence linking Cioni's reported teaching duties to Nancy's disappearance.

The claim is not new. On 1 May, a Facebook user asked whether Cioni had taught 'CSI evidence at the college' and attached what was described as a screenshot showing him teaching a CSI course. The commenter said the claim had circulated since 6 April.

However, the Facebook post does not establish that Cioni taught at a college, nor does it independently establish that he taught a Crime Scene Investigation course at BASIS Oro Valley.

Publicly available information identifies Cioni as a science and AP Biology teacher at the school. The material does not independently confirm that he taught a CSI course or that CSI techniques were taught as part of his AP Biology class.

Guthrie Family Not Suspects, Sheriff Says

Cioni and Annie Guthrie have faced considerable online scrutiny since Nancy disappeared, partly because of the couple's contact with Nancy on the night before she was reported missing.

Former NewsNation journalist Ashleigh Banfield previously discussed the possibility that Cioni could be a suspect. That characterisation was not adopted by law enforcement.

Sheriff Nanos subsequently said the Guthrie family, including all siblings and spouses, had been cleared as possible suspects. He said the family had been cooperative and described its members as victims.

Nanos reiterated that position months later, saying that the Guthrie family was 'not and have not been suspects' in the investigation.

He also explained that investigators could reconsider any person if genuinely new evidence emerged, but that general possibility did not mean the family had become suspects.

What Happened to Nancy Guthrie

Nancy Guthrie was last seen at her Catalina Foothills home after Cioni reportedly drove her there following dinner with Annie and Cioni on 31 January.

She was reported missing on February 1 after she failed to appear as expected. Investigators subsequently treated the disappearance as a criminal investigation and said they believed she had been taken against her will.

Authorities have released surveillance material and continued investigating the disappearance. Blood was reportedly found at the property and identified as Nancy's, while investigators have not publicly disclosed all of the forensic evidence gathered during the investigation.

As of publishing, there is currently no publicly established evidence that connects Tommaso Cioni to Nancy's disappearance.

The social-media claims about Cioni's alleged forensics teaching remain unverified. Pima County Sheriff Chris Nanos, meanwhile, has publicly maintained that the Guthrie family are not suspects in the investigation.

The sheriff's office has not commented on the latest social media claim. Investigators have urged anyone with tips to call 1‑800‑CALL‑FBI or the Pima County Sheriff's Office at 520‑351‑4900.