Protests are under way in dozens of American cities, a week after George Zimmerman was cleared of murdering unarmed black teenager Trayvon Martin.
Protesters want federal charges to be brought against Mr Zimmerman, 29, over the February 2012 incident.
A Florida jury agreed that the neighbourhood watch volunteer killed the 17 year-old in self-defence.
In his first comments, President Barack Obama admitted many black men in the US experienced racial profiling.
The protests against the court's decision are being led by the National Action Network, headed by civil rights activist the Reverend Al Sharpton.