What is a boy's life worth? The answer may depend on who is asking. It also may matter where the question is being raised.

Officials in Sanford, Florida, initially decided not to arrest neighborhood watch volunteer George Zimmerman after he fatally shot unarmed 17-year-old Trayvon Martin on Feb. 26. This past week, Zimmerman was charged with second-degree murder. Did Florida special prosecutor Angela B. Corey place a different value on the life of that young black victim than Sanford authorities did? Corey has said that "the search for justice has brought us to this moment" when she announced the charge against Zimmerman.

The murder charge doesn't settle the question raised by Martin's shooting. As Ohio State University law professor Michelle Alexander, the author of "The New Jim Crow: Mass Incarceration in the Age of Colorblindness," told the Christian Science Monitor, Martin's killing is "not an exceptional case except for the fact that the one who did the accosting while armed was a private citizen" rather than a police officer.