SANFORD, Florida (Reuters) - President Barack Obama called for calm on Sunday after the acquittal of George Zimmerman in the shooting death of unarmed black teenager Trayvon Martin, as thousands of civil rights demonstrators turned out at rallies to condemn racial profiling.
Zimmerman, cleared late on Saturday by a Florida jury of six women, still faces public outrage, a possible civil suit and demands for a federal investigation.
With civil rights activists clamoring for federal civil rights charges, the U.S. Justice Department said it was evaluating whether it has enough evidence to support prosecution of Zimmerman in federal court after his acquittal in Florida.
Zimmerman's lawyers argued he acted in self-defense the night of February 26, 2012, when, they say, Martin attacked Zimmerman inside a gated community in the central Florida town of Sanford. They accuse civil rights advocates of wrongly injecting the issue of race.
"It was such a shame. The whole case nearly destroyed George from day one ... . That they put a racism spin on this prosecution just hurt him very deeply," said John Donnelly, a close friend of Zimmerman who testified in the trial.
Critics contend Zimmerman, 29, who is white and Hispanic, wrongly suspected Martin, 17, of being a criminal because he was black. Zimmerman called police to report a suspicious looking person, then left his car with a fully loaded Kel Tec 9mm pistol concealed in his waistband.
A fight ensued in which Zimmerman suffered a bloody nose and head injuries, and Zimmerman shot Martin once in the heart.
The teenager had no criminal record and was staying in the neighborhood at the home of his father's fiancee. He had been walking back from a convenience store where he had bought candy and a soft drink.
Thousands of protesters chanting "No justice, no peace" gathered in New York City on Sunday to protest the acquittal, which prompted rallies across the country.
"I feel if we don't step it up, we're in trouble," said Prince Akeem, 20, of the Bronx. "It's young blacks being targeted and we have to stand up, stand up to the cops."
About 1,000 to 2,000 of the demonstrators abandoned the protest site at Union Square to march in the streets toward Times Square, slowing or stopping traffic. Police attempted to funnel the crowd into controlled lanes but were unable to.
Police attempted to halt the march about eight blocks short of Times Square, which was already packed with tourists, but the demonstrators made their way around the officers.
Saturday's not-guilty verdict was decried by civil rights leaders and protests were organized in several cities, including Boston, San Francisco, San Diego and Sacramento.
In Boston, about 500 racially mixed protesters left their demonstration site in the Roxbury neighborhood and started marching in the streets alongside police escorts on motorcycle and on foot. "They've been very orderly," Boston police superintendent William Evans said.
Around Sanford, some residents expressed relief at the verdict, while others said they failed to see how Zimmerman could have been acquitted.
"You said he's not guilty, but why would you say he's not guilty?" 28-year-old Robyn Miller said. "It's crazy."
Obama, who once said, "If I had a son, he'd look like Trayvon," called for a peaceful response to a case that polarized the U.S. public from the beginning, raising issues of racial profiling and gun control.
"We are a nation of laws and a jury has spoken," the first black U.S. president said in a statement. "I now ask every American to respect the call for calm reflection from two parents who lost their young son."
The jurors who deliberated for 16 hours over two days found Zimmerman not guilty of second-degree murder and manslaughter. All six women, who were sequestered for the three weeks of testimony, declined to speak to reporters and their identities were still sealed by the court.
If found guilty of the most serious charge of second-degree murder, Zimmerman could have faced life in prison. Instead, the jury cleared him of that charge and of manslaughter, which could have resulted in a 30-year sentence.
In Sanford at the largely black Allen Chapel A.M.E. Church, pastor Valarie Houston dedicated a Sunday morning prayer service to Martin.
"I am hurt. I am sad. I am disappointed and my heart is overwhelmed with pains," Houston said. "I thought in my heart that justice would be served."
Zimmerman, who showed little reaction when the decision was read, was unshackled from a monitoring device he had been wearing while on bail. He previously only left home in a disguise and body armor, his lawyer said.
His brother said he would remain out of public view for some time. Friends said the former neighborhood watch volunteer had recently spoken about the possibility of entering law school.
The tense drama that climaxed with the verdict had been building for more than a year, since police initially declined to arrest Zimmerman for shooting Martin, whose gray hooded sweatshirt has become a symbol of injustice for protesters.
The acquittal will weaken any wrongful death civil lawsuit that Martin's family might bring. Zimmerman's lead defense lawyer, Mark O'Mara, predicted Zimmerman would seek and win immunity from a civil suit.
A Justice Department spokesperson said in a statement on Sunday it would determine whether "the evidence reveals a prosecutable violation of any of the limited federal criminal civil rights statutes within our jurisdiction."
Additional reporting by Irene Klotz in Sanford, Chris Francescani, Adrees Latif and Victoria Cavalieri in New York, Ross Kerber in Boston, Mark Felsenthal and Paul Simao in Washington; Writing by Paul Thomasch and Daniel Trotta; Editing by Xavier Briand and Stacey Joyce