article_snippet: Martin Richard, eight, bled to death during the attack at the Boston Marathon in April 2013 .
article_snippet: Martin was one of three people killed on April 15, 2013, while more than 260 others suffered injuries.
article_snippet: Krystle Campbell, 29, also died in the attack . '
article_snippet: Dzhokhar Tsarnaev, 21, is charged with the attack, as well as shooting Massachusetts Institute of Technology police officer Sean Collier dead three days later.
article_snippet: Massachusetts Institute of Technology police officer Sean Collier brother, Tamerlan Tsarnaev, 26, died that night after a gunfight with police that ended when Dzhokhar ran him over with a hijacked car.
highlights_snippet: Martin Richard was among three young people killed at the Boston Marathon bombing in April 2013 .
  