Investigators are investigating a possible incident at the 84-year-old grandmother's Arizona home weeks before she was kidnapped. The Pima County Sheriff Chris Nanos, who has faced criticism over the 52-day search for Nancy Guthrie, confirmed that authorities have zeroed in on an evening three weeks before her kidnapping. The FBI's analysis of the incident is being conducted. The family has urged members of the Tucsonans to search their memories for potential information.