The Florida jury that found George Zimmerman not guilty of killing unarmed teenager Trayvon Martin relied on a controversial Florida law to reach its verdict. RFE/RL takes a look at what's behind the public protests and the legal action Zimmerman could still face.
Why did a Florida jury conclude that George Zimmerman acted legally when he shot Trayvon Martin?
He won on a claim of self-defense.
Zimmerman, 29, who is of mixed white and Hispanic descent, spotted 17-year-old Martin, who was black, walking through his neighborhood one night in February 2012. After summoning the police because he thought Martin looked suspicious, Zimmerman got in his truck and followed the teenager, a loaded handgun tucked into his waistband. When he got out and confronted Martin, Zimmerman said the unarmed youth attacked him.
"Obviously we are ecstatic with the results. George Zimmerman was never guilty of anything except protecting himself in self-defense," Zimmerman's defense lawyer, Mark O'Mara, said after the verdict.
"I'm glad that the jury saw it that way and I hope that everyone who thinks, particularly those who doubted George's reasons and doubted his background now understand that the jury knew everything that they knew was enough for them to find him not guilty."
Why are Stand Your Ground laws controversial?
The initial investigation of the Trayvon Martin shooting sparked discussion of Florida's Stand Your Ground law. It says a person can use deadly force to fight back if they feel their life is in danger, even if fleeing is an option.
A long-standing principle of U.S. law is that citizens have the right to use lethal force in their own homes in self-defense -- without an obligation to retreat.
In recent years, many states, including Florida, have passed laws extending that right to public places.
Advocates for gun rights and crime victims say these Stand Your Ground laws are needed so people can defend themselves in public places without fear of legal consequence. Some 20 states have the law.
But critics say the law almost always favors white shooters and actually encourages violence, because people feel freer to use guns during confrontations.
A study by Texas A&M University
found that murders and non-negligent manslaughters increased 8 percent in states that passed Stand Your Ground laws.
The Urban Institute's Justice Policy Center
found that a white person who kills a black person in a Stand Your Ground state is 354 percent more likely to be acquitted than if he had killed another white person.
It's worth noting that the same study found that verdicts of justifiable homicides are "exceedingly rare," consisting of less than 2 percent of all U.S. murders.
Why has the verdict aroused so much public anger?
Zimmerman's acquittal reinforced the belief of many Americans that the U.S. justice system is prejudiced against black people. Some are comparing the verdict to the 1955 acquittal of two white men accused of killing Emmett Till, a 14-year-old black boy. That case helped spark the civil rights movement.
The day after the verdict, thousands of people in several cities protested the judgment.
A protester named Dave Schleicher in New York City's Times Square spoke for many when he said: "It's just a completely gross miscarriage of justice, and I feel everybody -- white, black, from all backgrounds, really -- should be concerned and horrified by this situation. Anybody with any concern for social justice really should be appalled that something like this is happening in the United States of America."
Are the protests likely to become violent?
There have been arrests and smashed car windows but no serious violence so far.
President Barack Obama -- who before the trial said if he had a son, he would look like Martin -- issued a statement that said the case "has elicited strong passions" but added: "We are a nation of laws, and a jury has spoken. I now ask every American to respect the call for calm reflection from two parents who lost their young son."
Could Zimmerman face more legal action?
Zimmerman's legal troubles are far from over.
U.S. Attorney General Eric Holder said the Department of Justice's investigation begun last year into Martin's death will continue. Lawyers are examining evidence to see if Zimmerman violated any federal criminal civil-rights statutes.
Ben Jealous, the head of the National Association for the Advancement of Colored People (NAACP), told CBS News on July 14 that his group wanted to see federal charges filed.
"Now, we focus on ensuring that our justice system continues its course. There may be a civil action brought by the family but there should definitely be criminal actions brought by [the Department of Justice, DOJ]. And we have asked DOJ to continue their investigation; they are indeed continuing," Jealous said.
"We hope that once everything has happened that can happen here in Florida -- because DOJ often waits until the end [of a state trial] -- that DOJ will act and will hold Mr. Zimmerman accountable for what he has done."
The Justice Department has a long history of using federal civil-rights law to prosecute defendants who a state has acquitted.
But former U.S. Attorney Alan Vinegrad said this case may be hard to bring. "There are several factual and legal hurdles that federal prosecutors would have to overcome," he said. "They'd have to show not only that the attack was unjustified, but that Mr. Zimmerman attacked Mr. Martin because of his race and because he was using a public facility, the street.''
Martin's family is almost certain to file a wrongful-death civil lawsuit against Zimmerman. A victory would only bring monetary damages, but would be symbolic.
O.J. Simpson was famously acquitted in the deaths of Nicole Brown Simpson and Ronald Goldman, but a civil court found him guilty and ordered him to pay $25 million to the victims' families.