George Zimmerman has made his first courtroom appearance since he was charged with the fatal shooting more than six weeks ago of unarmed black teenager Trayvon Martin, as a judge agreed to seal some records in the case.
Zimmerman, dressed on Thursday in a dark gray prison-issued jumpsuit, looked intently at the judge throughout the hearing, which marked the beginning of a judicial process to determine the legal punishment for the killing of Martin.
He was charged on Wednesday with second-degree murder.
In an appearance that lasted less than five minutes, Zimmerman twice said "Yes sir" in addressing the judge in a courtroom at Florida's John E Polk Correctional Facility.
Judge Mark Herr set formal arraignment for May 29 and agreed to a stipulation by lawyers for both sides to seal some records.
The issue of whether Zimmerman would be released on bond was not addressed.
Mark O'Mara, one of Zimmerman's lawyers, told reporters after the hearing that he chose not to ask for bail immediately because it might "only arouse the fervor" around the highly-charged case.
O'Mara also said he wanted his client to be released on bond after he could secure a safe place for him to stay while he continues through the legal proceedings.
Martin's killer has been segregated from the John E Polk Correctional Facility's general population in a roughly 67-square-foot cell with a toilet and two beds, for his own safety, according to the local sheriff's office.
Zimmerman, 28, who is of mixed white and Peruvian ancestry, has been subjected to death threats and was in hiding from the public for weeks.
'Would look like Trayvon'
The killing of Martin, 17, on February 26 in Sanford, Flordia, has catalysed a debate about race relations and self-defence laws, punctuated by a series of demonstrations across the country.
Barack Obama, the US president, commented on the case, saying: "If I had a son, he would look like Trayvon."
O'Mara previously said he had hoped the fact of Zimmerman's arrest - the central demand of Martin's parents and others across the country for more than a month - would help to ease the emotional intensity.
At a later date when he is arraigned, Zimmerman will plead not guilty, O'Mara has said. If convicted of second-degree murder, he could face up to life in prison.
Until Wednesday, police had declined to arrest Zimmerman, citing Florida's "Stand Your Ground" law, which allows people to use deadly force when they believe they are in danger of getting killed or suffering great bodily harm.
Al Jazeera's Andy Gallacher, reporting from Florida, said Trayvon Martin's "family is happy, but remember, this took a long time to happen ... and while they are now somewhat satisfied, there's a long way to go before George Zimmerman appears before a jury".
Thousands of people had demonstrated in rallies in Sanford and around the nation, demanding Zimmerman's arrest and criticizing the police.
Civil rights activists say racial prejudice caused Zimmerman's view that Martin looked suspicious, and played a role in the police decision not to arrest him.