Learn more about Aaron Alexis, the gunman killed by police in Monday's Navy Yard shooting.
The picture emerging of the Aaron Alexis, the dead gunman in Monday's Navy Yard shooting, is a study in contrasts -- one of a man who practiced languages and meditated, and another of a cold-blooded killer.
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'Tis the season for family, friends, gifts, holiday parties -- and all the rules of etiquette that goes along with seasonal get-togethers. Make sure you're avoiding holiday faux pas this season with this handy guide.