The Boston Marathon Bombing One Year Later (video)

Police officers carry flags during a wreath-laying ceremony on the one year anniversary of the 2013 Boston Marathon Bombing, on April 15, 2014 in Boston, Massachusetts. Last year, two pressure cooker bombs killed three and injured an estimated 264 others during the Boston marathon, on April 15, 2013. Photo by Andrew Burton/Getty Images

One year after two bombs went off near the finish line of the Boston Marathon, the victims and law enforcement look back on a painful day.