By David Adams
MIAMI, April 1 (Reuters) - Thousands of protesters gathered in a downtown bayfront park on Sunday demanding the arrest of the neighborhood watch volunteer who shot and killed an unarmed black teenager, Trayvon Martin, in central Florida a month ago.
Civil rights leaders were joined by Martin's parents who were making their first major public appearance in the family's home city since a news conference on the steps of the Baptist Church where the funeral for their son was held last month.
Sunday's protest came a day after one of the largest demonstrations yet in Sanford, the central Florida town where Martin was killed.
The crowd gathered in an amphitheater with a "Justice for Trayvon" poster behind the stage.
Protesters called for the arrest of George Zimmerman, the 28-year-old neighborhood watch volunteer who shot Martin with a semiautomatic handgun. Zimmerman, a white Hispanic, was in his car about to drive to a store when he noticed Martin walking back to his father's fiancée's home after buying candy and iced tea on Oscar night, Feb. 26.
Zimmerman called 911 to report that Martin looked "suspicious" and followed him against the dispatcher's advice.
He later told police that he was walking back to his vehicle when Martin attacked him and that he fired his weapon in self defense after he was punched in the nose, knocked down and had his head slammed against a sidewalk.
Police refused to arrest Zimmerman citing Florida's controversial "Stand Your Ground" law, which allows the use of lethal force outside the home when a reasonable threat is perceived.
The case has sparked a public outcry from celebrities, politicians, civil rights activists and ordinary citizens who believe Zimmerman had judged Martin to be suspicious simply on the color of his skin and should have been arrested for the shooting.
More than two million people have signed a petition on Change.Org to demand justice in the case. President Barack Obama weighed into the matter in personal terms, comparing Martin to a son he might have had and calling for "soul searching" over how the incident occurred.
A special state prosecutor is examining the case and could decide as soon as this week whether charges should be filed. Federal investigators are looking into charges of racial bias.
Martin was visiting Sanford while serving a 10-day suspension from Dr. Michael M. Krop Senior High School in north Miami. His parents are divorced but both still live in Miami where his mother is a county housing agency employee and his father is a truck driver.
Martin's former classmates have held several smaller protests, including a school walkout by more than 1,000 students last month. Martin's mother, Sybrina Fulton, later urged students not to protest with walkouts, but to sign petitions, take part in organized rallies and pray.
Martin was reportedly a good student and was taking after-school classes in the hopes of becoming an aviation mechanic.
Betty Wright, a Grammy Award winning R&B artist and Miami native was scheduled to sing at Sunday's rally in support of the Martin family. "It is something where we need to stop and realize that this is like 2012 and it's unacceptable," she told NBC.
Wright, whose has an album due to be released on Wednesday, will be singing "Dry Well," a song written to honor her own 21-year-old son, Patrick Parker, who was fatally shot in 2005. His killer was also never arrested.
"And if I can lend a celebrity voice to it, because when my son died, the way I got through it was through the power of family and the power of prayer," Wright told NBC. "And I began to write it out, as I have always done the pain in my life." (Reporting By David Adams; editing by Christopher Wilson)