Thousands of people are gathering for nationwide rallies in the US to press for civil rights charges against former neighbourhood watch leader George Zimmerman, who was found not guilty over the death of unarmed teenager Trayvon Martin.
The Florida case has become a flashpoint in debates over guns, race relations and self-defence laws. Mr Zimmerman identifies himself as Hispanic. Trayvon was black.
The Rev Al Sharpton's National Action Network has organised the "Justice for Trayvon" rallies outside federal buildings in 100-plus cities: from New York and Los Angeles to Wichita, Kansas, and Birmingham, Alabama. Mr Sharpton wants the justice department to pursue a case.
On Saturday morning in Manhattan, Trayvon's mother, Sybrina Fulton, told supporters, "Today it was my son. Tomorrow it might be yours."
Earlier president Barack Obama called on Americans to do some soul-searching over the death of the teenager, delivering an emotional public reflection on race that was rare for the country's first black president. Empathising with the pain of many black Americans, Mr Obama said the killed 17-year-old "could have been me 35 years ago". He said the case conjured up a hard history of racial injustice "that doesn't go away".
Although Mr Obama has written about his own struggles with racial identity, the surprise speech marked his most extensive discussion of race as president and an unusual embrace of the longing of many African-Americans for him to give voice to their experiences. "I think it's important to recognise that the African-American community is looking at this issue through a set of experiences and a history that doesn't go away," Mr Obama said.
In many ways, it was the frank talk on what it can be like to be black in America that many African-Americans had been waiting to hear. "Black people and brown people everywhere feel like they've been heard," said Angela Bazemore, 56, an administrative assistant who lives in New York City.
A Florida jury last week acquitted Mr Zimmerman of all charges in the February 2012 shooting of Trayvon, who was unarmed. The verdict was cheered by those who agreed that Mr Zimmerman was acting in self-defence, while others protested the outcome, believing Mr Zimmerman, who identifies himself as Hispanic, had targeted Trayvon because he was black.
Trayvon was staying in the gated community where Mr Zimmerman lived and had gone out on a rainy evening last year to buy snacks at a store. Mr Zimmerman, who was armed with a handgun and was part of a neighbourhood watch organisation, spotted Trayvon and called authorities to report he thought the teenager was acting suspiciously. Against the advice of an emergency dispatcher, who said police were on their way, Mr Zimmerman followed and shot the teenager when a scuffle or fight broke out.
Despite his emotional comments on the case, Mr Obama appeared to signal that the justice department was unlikely to file federal civil rights charges against Mr Zimmerman. Traditionally, he said, "these are issues of state and local government", and he warned that the public should have "clear expectations."