MIT police officers stand at attention outside the media-swamped federal courthouse in Boston on July 10. Under tight security, Boston Marathon bombing suspect Dzhokhar Tsarnaev made his first public appearance since he was captured on April 19 to attend his arraignment. The 19-year-old pleaded not guilty to charges of using weapons of mass destruction to kill three people and wound more than 260 others. Prosecutors have also charged Tsarnaev in the shooting death of 27-year-old Sean Collier, an MIT police officer. At least three dozen victims and survivors of the April 15 attack were reportedly present in the courtroom to watch the initial proceedings in what is likely to be a long, drawn-out case. (AP Photo/Winslow Townson)

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