Newtown clergy plant crosses for gun control More than 3,000 symbolic grave markers were placed in front of the US Congress in Washington D.C. on Thursday. They're meant to represent the number of people killed in gun violence since the mass-shooting in Newtown, Connecticut, last December. Leaders from several religions, some of them from Newtown, began a 24-hour vigil to call for the Senate to pass stricter gun control laws. Images and soundbites.