A Death in the Stairwell | Post Mortem

"48 Hours" correspondents Anne-Marie Green and Peter Van Sant discuss the case of Alison Davis on "Post Mortem." Davis' husband, Kevin, was found with a fatal injury at the bottom of their stairs at home. They examine why investigators felt Alison's call to 9-1-1 seemed suspicious and the courtroom battle between two doctors' testimonies about how Kevin died.