Local residents attend a candlelight vigil in the Dorchester neighborhood of Boston, Massachusetts, on April 16, 2013 where eight-year-old Boston Marathon explosion victim Martin Richard lived. A Little League baseball player, Martin lived in a blue Victorian house in working-class Dorchester - a Boston neighborhood dotted with "Kids at Play" traffic signs and budding trees - with his parents Bill and Denise, sister Jane, 7, and brother Henry, 10. Martin's mother and sister were seriously injured. #

Boston Marathon runners (L to R) Lisa Kresky-Griffin, Diane Deigmann and Tammy Snyder embrace at the barricaded entrance at Boylston Street near the finish line of the Boston Marathon in Boston, Massachusetts, on April 16, 2013. #

Members of the New York Yankees and the umpires bow their heads during a moment of silence for those killed in a bomb blast at the Boston Marathon on April 15, before their MLB Interleague game with the Arizona Diamondbacks at Yankee Stadium in New York, on April 16, 2013. #

In Atlanta, Georgia, runners observe a moment of silence before the start of an organized memorial run to show solidarity with victims of the Boston Marathon bombing, on April 16, 2013. #

Runners jog along Peachtree Street as part of an organized moment of silence and memorial run to show solidarity with victims of the Boston Marathon bombing, on April 16, 2013, in Atlanta. #

A young runner collects his thoughts in a church blocks away from the scene of yesterday's bombing attack at the Boston Marathon on April 16, 2013 in Boston, Massachusetts. #

A crushed water cup blows onto the sidewalk in front of a makeshift memorial, a day after two explosions near the finish line of the Boston Marathon, on April 16, 2013. #

In Beijing, China, people set up candles and flowers as they pray for victims of Monday's Boston Marathon bombings, on April 16, 2013. The third fatal victim of the attack was a Chinese citizen whose identity was not being made public at the request of the victim's family, the Chinese Consulate in New York said in a statement on Tuesday. Another Chinese citizen was injured and in stable condition after surgery, the statement said. #

The New York Islanders stand for a moment of silence to commemorate the tragedy at the Boston Marathon prior to their game against the Florida Panthers at the Nassau Veterans Memorial Coliseum in Uniondale, New York, on April 16, 2013. #

Patty Campbell speaks to reporters outside her home in Medford, Massachusetts, on April 16, 2013. Campbell's daughter, Krystle Campbell, was killed in Monday's bombings at the finish line of the Boston Marathon. #

In Miami, Florida, runners stand together during the playing of the National Anthem as the Baptist Health South Florida Brickell Run Club honors the victims of the Boston Marathon bombings, on April 16, 2013. The event drew approximately 1,000 people who wanted to honor the three people killed in the Boston bombing as well as the over one hundred who were injured. #

A building at the Massachusetts Institute of Technology is lit up in red, white and blue as a tribute to those who were killed or injured in the explosions at the Boston Marathon in Cambridge, Massachusetts, on April 16, 2013. #

Boston Marathon runner Megan Cloke pauses after leaving flowers on the doorstep of eight-year-old bombing victim Martin Richard's home in the Dorchester neighborhood of Boston, on April 16, 2013. #

A runner shows a banner reading: "Boston we are with you - Belgrade runners" in an organized memorial run to show solidarity with victims of the Boston Marathon bombing, on April 16, 2013, in Belgrade, Serbia. #

A man holds a candle as he joins others around the pond in the Public Garden after a candlelight interfaith service at Arlington Street Church, on April 16, 2013 in Boston, Massachusetts. #

People gather with candles during a vigil for eight-year-old Martin Richard, from Dorchester, who was killed by an explosion near the finish line of the Boston Marathon in Garvey Park in Boston, on April 16, 2013. #

Lizzie Lee, 56, of Lynwood, Washington, who was participating in her first Boston Marathon and 11th overall, holds a candle and a flower on Boston Common during a vigil for the victims of the Boston Marathon explosions, on April 16, 2013. #

Shane Magness, a student at Oklahoma Christian University, bows his head in prayer for the victims of the Boston Marathon bombing, at the Oklahoma City National Memorial in Oklahoma City, on April 15, 2013. On Friday, Oklahoma City will observe the 18th anniversary of the April 19, 1995, bombing of the Alfred P. Murrah Federal building that killed 168 people and injured hundreds more. #