The search for Nancy Guthrie, an 84-year-old woman missing from her home in Tucson, Arizona, is facing significant hurdles due to the challenging terrain of a nearby desert wash. Dave Smith, a retired lieutenant with the Arizona Department of Public Safety, explained that the dense brush in the area can obscure visibility and complicate evidence collection. He noted that rain can quickly wash away footprints and other crucial evidence, making the investigation particularly difficult. Smith also raised concerns about potential ties to Mexico, suggesting that Guthrie may have been taken across the border, which could complicate the investigation further. He indicated that the authorities might have intentionally downplayed these connections to keep federal agencies from becoming involved. The neighborhood's proximity to the border town of Nogales, just 60 miles away, adds to the complexity of the case, as it could provide opportunities for a suspect to blend into a larger urban area.