A neighborhood watch guard charged with second-degree murder in the controversial killing of an unarmed US black teenager appeared briefly in court for the first time Thursday.

George Zimmerman It was Zimmerman's first public appearance since he fatally shot 17-year-old Trayvon Martin in late February while the teenager was walking through a gated Florida community, in the town of Sanford.

The judge told Zimmerman he had set May 29 as the date for a hearing for his arraignment when he will be formally read the charges and will be allowed to apply for bail.

Looking alert and with closely shaven hair and beard, Zimmerman walked into court in handcuffs wearing a short-sleeved slate-grey prison jumpsuit.

Speaking just once, Zimmerman answered simply "yes sir" when asked by judge Mark Herr if he was making his first appearance in the case and if he was represented by lawyer Mark O'Mara.

The killing has triggered nationwide anger amid suspicions that it was racially motivated.

Zimmerman, 28, has said he was acting in self-defense, after the youngster apparently knocked him to the ground with one punch and battered his head against the sidewalk.

Police booking photographs released by the Seminole County Sheriff's Office on Wednesday shows George Zimmerman after being taken into custody. Prosecutors Wednesday charged a neighborhood watch guard with second-degree murder in the killing of an unarmed US black teenager that sparked nationwide anger amid suspicions it was racially motivated. (AFP Photo)