A Florida neighbourhood watch volunteer has been charged with second-degree, unpremeditated murder over the death of unarmed black teenager Trayvon Martin.
George Zimmerman, 28, turned himself in on Wednesday and is now in custody, special prosecutor Angela Corey said.
Trayvon Martin's parents said the charge was a first step towards justice but that there was "a long way to go".
Mr Zimmerman was not arrested in the weeks after he shot the 17-year-old on 26 February. He claimed self-defence.
He told police the youngster had attacked him, banging his head against the pavement, after Mr Zimmerman pursued him for looking suspicious.
The Martin family claims he acted in cold blood, suspecting the high school junior because of his race and dress.
Ms Corey told reporters: "Today we filed an information charging George Zimmerman with murder in the second degree."
"We did not come to this decision lightly. Let me emphasise that we do not prosecute by public pressure or petition," she added, in a reference to the intense media scrutiny that has surrounded the case in recent weeks.
Ms Corey added that no bail had yet been set for Mr Zimmerman. She did not disclose Mr Zimmerman's current location, but indicated that he would appear in court within 24 hours.
He was later transferred to jail in Seminole County before his court appearance.
Ms Corey said she was concerned that the intense media attention the shooting had attracted could make it a difficult case to try.
"Both the state and the defence are entitled to a fair and impartial jury. It is regrettable that so many facts and details got released and misconstrued," she added.
In the wake of the announcement, Trayvon Martin's mother and father appeared alongside civil rights leader Al Sharpton to hail the charge against George Zimmerman.
"We just wanted an answer, and we got it," Sybrina Fulton said.
"A heart has no colour - it is not black, it is not white. It's red," she added, her voice cracking with emotion.
His father, Tracy Martin, said more effort and more faith would be required from those seeking justice.
After the charges against him were made public, Mr Zimmerman's new defence lawyer, Mark O'Mara, said his client seemed lucid, and he was "not concerned about his mental well-being right now".
Mr O'Mara said he had been appointed to the case about 90 minutes before Ms Corey unveiled the charges against his client and he had not yet had time to look at the evidence.
However, Mr Zimmerman was likely to plead not guilty, Mr O'Mara said.
On Tuesday, Mr Zimmerman's previous lawyers announced they were withdrawing as his legal counsel as they had lost contact with him and did not know where he was.
The case highlights Florida's controversial "stand your ground" law, which grants individuals leeway to use deadly force if they feel seriously under threat.
Trayvon Martin was walking home from a local shop carrying a bag of sweets and a can of iced tea when he was approached by Mr Zimmerman.
The neighbourhood watch volunteer had told a police dispatcher he thought Martin, who was wearing a hooded sweatshirt, looked suspicious.
According to 911 emergency calls released afterwards, the dispatcher advised Mr Zimmerman not to go after the young man. But minutes later a confrontation ensued, leading to the fatal shooting of Martin.
The case has become a national issue, with rallies, marches and other protests in favour of bringing a charge against Mr Zimmerman.
President Barack Obama spoke out, saying that if he had a son he would probably "look like Trayvon".