In a Wednesday memorial service for Arizona shooting victims, President Obama urged Americans to unite on behalf of slain 9-year-old victim Christina Green.
Christina Green: Obama Calls for Unity over Slain 9-Year-Old Christina Green
Christina Green: President Obama, in a Wednesday memorial service for Arizona shooting victims, urged Americans to unite on behalf of slain 9-year-old victim Christina Green.

US President Barack Obama attends the memorial event, Together We Thrive: Tucson and America, at the McKale Memorial Center in Tucson, Arizona, on January 12, 2011. Jewel Samad/AFP/Getty Images
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