SAVANNAH GUTHRIE'S MOM MISSING: DAY 17

While male DNA found on a glove near Nancy Guthrie's home did not yield a hit in the national CODIS database, this is not a dead end. The DNA is now being processed through state-level databases, which have different entry thresholds and can facilitate familial testing. Additionally, investigators can explore public and private genealogy databases, requiring legal process, to find relatives of the unknown male profile. This multi-pronged approach is crucial because national databases have stringent requirements, and not all offenders or suspects are included.

Tammy Ballard, a DNA crime scene consultant, explained that the national database (CODIS) has high bars for profiles to prevent false positives, and state labs can access additional profiles and perform familial testing. Andrew Black, former FBI, noted the possibility of tapping into public and private genealogy databases with legal process.

Investigators are deploying 'Bluefi' technology, a powerful Bluetooth scanner, on low-flying drones to locate Nancy Guthrie's pacemaker. This technology can detect Bluetooth signals from 660-800 feet away, significantly extending the range of typical personal devices. Crucially, pacemakers, like other Bluetooth devices, possess a unique MAC address (similar to a VIN number), allowing the Bluefi system to filter out all other signals and specifically identify her device. This method, adapted from cybersecurity and search-and-rescue applications, offers a targeted approach to finding a missing person with an implanted medical device.

Scott Iiker, a digital forensics expert, detailed Bluefi's capabilities, its range, and the ability to filter for a specific MAC address. He confirmed that pacemakers have unique MAC addresses. Dave Mack, investigative reporter, confirmed the technology's extended range and its deployment on drones.

Key items worn by the suspect, including an Ozark backpack, jacket, face mask, and a specific polyester holster, have been identified as products sold at Walmart. The holster, in particular, was reportedly available at only two Walmart locations in Tucson. This retail information provides a concrete lead for investigators, who can leverage Walmart's extensive loss prevention camera systems and transaction records. While credit card purchases would be ideal for direct identification, even cash purchases could be linked to video footage, though video retention limits (30-60 days) pose a challenge.

Andrew Black, former FBI, confirmed the significance of the Walmart leads, especially the holster's limited availability. He highlighted Walmart's camera systems and the potential for credit card transaction data, while acknowledging the challenge of video retention for cash purchases.

Despite the suspect potentially wearing gloves, experts believe he likely left 'touch DNA' within Nancy Guthrie's home. This occurs through cross-contamination, where a gloved hand touches an item on the perpetrator's person (like a holster, face mask, or pen) that already carries their DNA, and then transfers that DNA to surfaces inside the residence. Furthermore, items handled by mouth, such as a 'light bite' flashlight, are prime sources of saliva DNA. This concept underscores that even seemingly careful perpetrators can inadvertently leave behind critical forensic evidence.

Tammy Ballard, a DNA criminalist, explained how perpetrators wearing gloves can still leave their DNA through cross-contamination by touching personal items (holster, face mask) and then other surfaces. She specifically mentioned the 'light bite' flashlight as a strong source of saliva DNA.