The family of 17-year-old Martin and scores of supporters who took to the streets had demanded Zimmerman's arrest and justice for Trayvon after he killed the unarmed teenager.

The decision to charge Zimmerman with murder was announced at a press conference in Florida last night.

He had originally been freed without charge after the killing on February 26. Zimmerman insisted he had shot Trayvon in self-defence and cited the Florida law that states there is no duty to retreat, and that a Floridian can "stand his or her ground and meet force with force, including deadly force" if he feels threatened.

Zimmerman had reported a "suspicious male" to a police dispatcher on the night of the shooting and continued to follow Trayvon against the dispatcher's advice. Zimmerman claimed the youth had broken his nose, but CCTV footage of Zimmerman arriving at the police station that night seems inconclusive.

Special prosecutor Angela Corey said of the decision to charge Zimmerman: "I can tell you we did not come to this decision lightly.

"We prosecute based on the facts of any given case, as well as the laws of the state of Florida. We have to have a reasonable certainty of conviction before we file charges.

She added that "the search for justice for Trayvon Martin ... has brought us to this moment".

Zimmerman's attorney Mark O'Mara said his client will plead not guilty and added that he is "hoping that the community will calm down" now that charges have been filed and the case will be thoroughly investigated.

Picture: Getty