The contractor who killed 12 people at the Washington Navy Yard had been hearing voices and was undergoing treatment weeks before the rampage. The shooting raises new questions about security ... more 
The contractor who killed 12 people at the Washington Navy Yard had been hearing voices and was undergoing treatment weeks before the rampage. The shooting raises new questions about security clearances and vetting government contractors. (Sept. 17) less 
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Wed, Sep 18, 2013 10:53 AM EDT