US Neighbourhood Watch volunteer George Zimmerman has entered a plea of not-guilty to the charge of second-degree murder.
Zimmerman did not appear in the Florida court and has waived his right to a speedy trial in order to have more time to prepare for the high profile case.
In the meantime he remains free on bail while being monitored by the authorities.
Zimmerman shot dead 17-year-old Trayvon Martin during a confrontation in gated community in Sanford, Florida in February.
The case has caused a racism storm after his family accused Zimmerman of following and shooting Trayvon because he was black and wore a hoody. Zimmerman who claims he shot the youngster in self defence was only charged six weeks later after protests by his parents and civil rights groups.