"Growing pressure" as Nancy Guthrie search passes six months

Six months after Nancy Guthrie was taken against her will from her Arizona home in the middle of the night, there are no suspects or major leads and the case seems to be stalled, a source close to the investigation tells me. "There is plenty of blame to go around, but there is growing pressure to solve this case," the source said. "This case has struck a chord — people are watching very closely. This can't go on for another six months." Savannah Guthrie, the "Today" show co-host and Nancy's…