Thousands joined “Justice for Trayvon” rallies yesterday to demand that George Zimmerman face federal civil rights charges, a week after a jury found him not guilty in the death of unarmed black teenager Trayvon Martin.

“Trayvon was no burglar. He had a drink and some candy,” Martin’s mother, Sybrina Fulton, told the rally in New York - one of more than 100 around the country.

“He had every right to walk within that community to go back to the house where he came from,” Fulton said of Martin before the February 2012 shooting by the neighbourhood watch volunteer in Sanford, Florida. “Those are the facts that we need to stand on because today it was my son, tomorrow it might be yours.”

Zimmerman’s acquittal on all charges by a Florida jury was met with widespread outrage in the African-American community, sparking a national debate over the role racial profiling may have played in the 17-year-old’s death.

Even the White House has joined the week-long outpouring of protest and worry.

On Friday, Barack Obama, the nation’s first black president, recalled the discrimination he has experienced in his own life, being followed in a department store or hearing car doors being locked as he crossed a street.

“Trayvon Martin could have been me 35 years ago,” Obama said.

The uproar comes as the nation prepares to commemorate the 50th anniversary of Martin Luther King Junior’s “I have a dream” speech in August - a watershed event in the struggle for racial equality in the US.

In Miami, an estimated 500 people gathered near the federal courthouse bearing signs such as “We shall not forget”.

Martin’s father, Tracy, was in attendance and thanked the crowd for its support.

“The death of my son, we believe, has to make changes in our society and repeal the laws that allow killing somebody just because someone thinks (he or she) is suspect,” Martin said.

Martin’s parents and the civil rights community are launching a campaign against so-called “stand your ground” laws in more than two dozen states, including Florida. The laws allow use of lethal force if someone thinks their life is in danger.

Zimmerman argued he killed Martin in self defence after he stalked the teenager in his car and then on foot. While the law was not referenced in the trial, it had been used by the Sanford police to justify their failure to launch an investigation or arrest Zimmerman for more than six weeks after the killing.

Civil rights group say the laws are used disproportionately in favour of whites and against blacks. The US Commission on Civil Rights has launched an investigation into whether the laws have a racial bias, and both Obama and Attorney General Eric Holder, who is also African-American, vowed in recent days to evaluate the laws.

Yesterday’s protests were organised by the National Action Network, led by civil rights activist and minister Al Sharpton.

The US Justice Department is reviewing the case to see whether any federal civil rights statutes had been violated, and whether it could take any fresh legal action.