India, Nov. 12 -- More than nine months after Nancy Guthrie's disappearance, a retired homicide detective has suggested that investigators are putting "too much" faith in DNA evidence. Savannah Guthrie's mother was last seen at her home in the Catalina Foothills area near Tucson on the evening of January 31. She was reported missing by her family on February 1.

In an interview with NewsNation's Ashleigh Banfield, retired homicide detective Chris McDonough questioned how investigators are handling the case. Banfield expressed her frustration about the emphasis on unidentified male DNA found in the home. The sample is mixed and has reportedly undergone extensive testing.

"One thing that kind of makes me crazy about this case is that so mu...