Mass shootings, mental illness

Police work the scene on M Street, SE in Washington near the Washington Navy Yard on Monday, Sept. 16, 2013. The U.S. Navy says one person is injured after a shooting at a Navy building in Washington. Police and emergency crews gathered Monday morning outside the Naval Sea Systems Command Headquarters building, where the shooting was reported.  (AP Photo/Jacquelyn Martin)
Police work the scene on M Street, SE in Washington near the Washington Navy Yard on Monday, Sept. 16, 2013. The U.S. Navy says one person is injured after a shooting at a Navy building in Washington. Police and emergency crews gathered Monday morning outside the Naval Sea Systems Command Headquarters building, where the shooting was reported.  (AP Photo/Jacquelyn Martin)

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    Mass shootings, mental illness

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In the aftermath of Navy Yard shooting this week, Christine Romans looks at a possible cause behind this and other tragedies: the state of mental health in America.