On the evening of Feb. 26, 2012, Trayvon Martin, 17, was shot and killed by George Zimmerman, 28. At the time of the shooting, an unarmed Martin was walking to the home of his father’s girlfriend in a Sanford gated community. Zimmerman was armed with a handgun and working as a community crime watch captain. Martin was African-American, and Zimmerman was Hispanic. Shortly before the shooting, Zimmerman was on the phone with a 911 dispatcher, who admonished him not to follow Martin. In the following days, an eyewitness came forward to report that Martin was the aggressor, while Zimmerman cried...