Colorado shooting: Massacre at Aurora movie theater
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A gas mask was marked as the first piece of evidence in a criminal investigation outside the parking lot behind the Century 16 movie after a shooting at the theatre Friday, July 20, 2012. A gunman wearing a gas mask set off an unknown gas and fired into the crowded movie theater killing 12 people and injuring at least 50 others, authorities said. The suspect is identified as 24-year-old James Holmes.