Americans angry at the acquittal of George Zimmerman in the death of black teen Trayvon Martin protest in Los Angeles, California on Sunday. (AFP-Yonhap News)
President Barack Obama appealed for restraint Sunday as thousands marched across the country protesting the acquittal of a man who gunned down an unarmed black teenager.
A Florida jury late Saturday found volunteer watchman George Zimmerman not guilty of murdering 17 year-old Trayvon Martin in a racially-charged trial that transfixed much of the country for weeks.
Crowds took to the streets to protest the verdict Sunday in cities including Boston, San Francisco and Los Angeles.
In New York, several thousand rallied in Times Square waving signs with portraits of Martin, while others wore "hoodie" sweatshirts, despite the searing heat, as the teen did the night he was killed.
"The man was armed, the kid was not, and the man with the gun got away," said protester Carli VanVoorhis, 21. "If we say it was not a racial issue, we would be lying."
Despite the large crowds the various marches were largely peaceful, though windows were smashed and cars vandalized in pre-dawn protests in Oakland, California.
Obama, the first black US president, urged Americans to step back and accept the trial verdict.
"We are a nation of laws, and a jury has spoken," Obama said in a statement. "I now ask every American to respect the call for calm reflection from two parents who lost their young son."
Zimmerman, 29, was accused of pursuing Martin, 17, through a gated community in the town of Sanford, and shooting him during an altercation on the rainy night of February 26, 2012.
The defense successfully argued that Zimmerman shot Martin in self-defense after the teen wrestled him to the ground and was slamming his head against the pavement.
According to Florida's controversial "Stand Your Ground" law, people who fear for their lives can use deadly force to defend themselves without having to flee a confrontation.
"We should ask ourselves, as individuals and as a society, how we can prevent future tragedies like this," Obama said. "As citizens, that's a job for all of us. That's the way to honor Trayvon Martin."
Obama last year spoke emotionally about the case, noting that if he had a son he would "look like Trayvon."
The trial divided those who believed that Zimmerman, who is Hispanic, had racially-profiled Martin, and those who believed he acted in self-defense.
A racial divide was evident Sunday in Sanford pastor Valerie Houston's sermon.
"Dr (Martin Luther) King (Jr) stated, the daily life of the Negro is still in the basement of the Great Society," she said. "And today I state, the daily life of my people is still enslaved to a white supremacist society."
Martin's parents -- father, Tracy, and mother Sybrina Fulton -- asked the public before the verdict to respect the trial outcome, and afterwards gave thanks for the outpouring of support they received over the past year.
The Martin family's attorney Benjamin Crump declined to say whether they would file a civil lawsuit against Zimmerman, but said "they are going to certainly look at that as an option."
"They deeply want a sense of justice. They deeply don't want their son's death to be in vain," he told ABC News's "This Week."
Community leaders called for non-violent demonstrations after the verdict.
"There will be protests, but they must be carried out with dignity and discipline and let no act discredit the legacy of Trayvon Martin on the appeal of his family," civil rights leader Reverend Jesse Jackson said on CNN.
The NAACP, the largest US civil rights group, urged supporters to sign a letter asking Attorney General Eric Holder to file civil rights charges against Zimmerman.
"The most fundamental of civil rights - the right to life - was violated the night George Zimmerman stalked and then took the life of Trayvon Martin," read the NAACP letter.
The US Justice Department said Sunday it will resume its probe into whether hate crime charges can be brought against Zimmerman following the Florida trial.
Federal prosecutors "will determine whether the evidence reveals a prosecutable violation of any of the limited federal criminal civil rights statutes within our jurisdiction," it said in a statement.
Florida police initially declined to press charges against Zimmerman, sparking mass protests in several US cities. He was eventually arrested in April 2012 and charged with second-degree murder and manslaughter.
With the acquittal, Zimmerman's lawyers told the Washington Post that they will immediately resume a defamation lawsuit against NBC News for selectively editing a phone call to police which made their client seem like a racist. (AFP)