Seminole County Circuit Judge Mark E. Herr ordered George Zimmerman, 28, held pending a bond hearing and formal arraignment on second-degree murder charges May 29 before Judge Jessica J. Recksiedler.
No plea was entered during Thursday's brief teleconference hearing. Zimmerman answered, "Yes, sir," to acknowledge he understood the charges.
Both defense attorney Mark O'Mara and special prosecutor Angela Corey agreed records in the case should be sealed.
Zimmerman has admitted shooting and killing Martin, 17, Feb. 26 as the teen walked through a gated Sanford neighborhood. The shooting sparked outrage in the black community and police initially declined to file charges, citing Florida's Stand Your Ground law.
Zimmerman, who is a white Hispanic, surrendered to police Wednesday.
Earlier Thursday, Martin's mother said she believes the shooting "was an accident."
"I believe it was an accident,'' Martin's mother, Sybrina Fulton, told NBC's "Today" show Thursday. "I believe that it just got out of control and [Zimmerman] couldn't turn the clock back. I would ask him, did he know that that was a minor, that he was a teenager, and that he did not have a weapon?"
Martin's parents watched news coverage of Zimmerman's arrest from Washington, D.C.
"What went through my mind was that finally the person who shot and killed my son was going to be held accountable for what he has done," Fulton said. "Even if [a trial] means he may be found not guilty, we just want him to be held accountable for what he's done. By him not being arrested, that would not have been done. We are happy that he was arrested so that he can give his side of the story.''
O'Mara said Zimmerman will plead not guilty.
"He's very stressed, very tired," O'Mara said Thursday. "As for the Martin family, it's been a difficult several weeks for him. He wants to be out to help with his defense, but he's doing OK.
"I was surprised that they chose [the murder charge] at that level," O'Mara said. "I have no idea what the facts are yet, so I know that Ms. Corey looked at her case, decided to charge what she could or should, and we'll deal with it."
Corey said the prosecutor's office conducted a thorough investigation before issuing the charges.
"We did not come to this decision lightly," Corey told a news conference broadcast live. "We do not prosecute by pressure or petition."