George Zimmerman (L) talks to his attorney Mark O'Mara during his bond hearing in Sanford, Florida, on April 20
The Florida neighborhood watch volunteer charged with second-degree murder over the high-profile shooting of unarmed black teen Trayvon Martin entered a plea of not guilty on Monday.
"The defendant, by and through his undersigned attorney, enters a written plea of not guilty to the charges now pending against him," read a court document waiving George Zimmerman's right to appear at his May 8 arraignment.
The plea came hours after Zimmerman was released from jail on a $150,000 bond, pending trial. He is believed to be residing out of the state for his own safety after receiving a string of threats in the racially-charged case.
Television pictures showed the 28-year-old, wearing jeans and a bulky brown jacket that appeared to conceal a bullet-proof vest, leaving a jail in Sanford, Florida shortly after midnight and stepping into a white car.
His release followed a dramatic court hearing on Friday in which he unexpectedly took the stand and apologized directly to the victim's parents, who dismissed it afterwards through a lawyer as insincere and "self-serving."
Prosecutors say 17-year-old Martin was simply "minding his own business" when he was accosted and shot dead by Zimmerman in late February after buying some candy and a bottle of iced tea from a local store in Sanford.
Zimmerman maintains he was acting in self-defense as Martin assaulted him.
Martin's family and supporters allege he was a victim of racial profiling, and the case sparked angry demonstrations in black communities across the country when police initially decided not to press charges.
Sanford city commissioners voted Monday to reject police chief Bill Lee's resignation after he offered to step down permanently because of the controversy.
Zimmerman, who surrendered his passport and is wearing electronic monitoring tags, is believed to have gone into hiding in a different state after receiving death threats over the killing of Martin on February 26.
Martin's family said it respected the judicial process but were "devastated by him being able to walk the streets," attorney Daryl Parks told CNN.
"It's with a very, very heavy heart that they've seen him walk freely late last night back into the public," Parks said.
Zimmerman admits tracking Martin through a gated Sanford community after viewing him as suspicious, but insists he shot purely in self-defense after being assaulted.
Police initially declined to arrest him, citing Florida's "Stand Your Ground" law that allows deadly shooting if in self defense.
Zimmerman apologized to Martin's parents at Friday's hearing, telling them in his first public comments since the shooting: "I'm sorry for the loss of your son."
But the family expressed anger after the proceedings, both at the apology and at the judge's decision to allow Zimmerman to be released pending trial.
Prosecutor Bernie De La Rionda had urged the judge to deny bail or at least put it at $1 million.
Judge Kenneth Lester ultimately set bail at $150,000 but imposed conditions including electronic GPS tracking, a dusk-to-dawn curfew and a requirement for him to report every three days to the authorities.
Zimmerman had to post 10 percent of the bail amount, or $15,000, to make bail.
Dale Gilbreath, an investigator in the case, acknowledged at Friday's hearing that there was no direct evidence to say who threw the first blow in the confrontation, other than the fact Zimmerman had been following Martin.
If convicted, Zimmerman could face life in prison.