In the early hours of Jan. 1, 2009, Oscar Grant III, unarmed and lying 
face down on a subway platform in Oakland, Calif., was shot in the back 
by a white Bay Area Rapid Transit police officer. The incident, captured
 on video by onlookers, incited protest, unrest and arguments similar to
 those that would swirl around the killing of Trayvon Martin in Florida a
 few years later. The deaths of these and other African-American young 
men (Mr. Grant was 22) touch some of the rawest nerves in the body 
politic and raise thorny and apparently intractable 
issues of law and order, violence and race.
 NYT