Zimmerman did not speak during proceedings at the Sanford, Fla., courthouse.
Instead, he was given a date for his formal arraignment on second degree murder charges: May 29 before Seminole County Judge Jessica Recksiedler.
Wearing a gray prison jumpsuit with his hands cuffed in front, Zimmerman appeared significantly slimmer than he did in his ubiquitous 2005 mug shot.
Zimmerman is being held in protective custody for his own safety, said his lawyer, Mark O’Mara, who revealed he is working pro bono.
O’Mara did not ask for bail, saying he has decided to wait until attention has shifted from the incident.
“It’s an attempt to calm the case down,” he said.
“I hope to have him released on bond (in a few weeks),” O’Mara said. “I hope to have a place for him to be safe.”
Zimmerman was arrested Wednesday, 45 days after cops let him walk free after shooting Trayvon, an unarmed 17-year-old that Zimmerman thought looked “suspicious.”
Furor over the case led state prosecutors to start their own probe, which resulted in the unexpectedly serious second degree murder charge.
If convicted, Zimmerman faces a minimum of 25 years in prison or a maximum of life behind bars without parole.
“We’ve charged what we thought was appropriate, and we’ll leave it at that,” said prosecutor Bernie de la Rionda, refusing to address the gulf between letting Zimmerman go free and a second degree murder charge.
He wouldn’t say if the state will oppose granting Zimmerman bail.
Under Florida’s controversial Stand Your Ground law, which Zimmerman invoked to claim self-defense in the shooting, Zimmerman can request immunity from a judge.
The judge must decide if he was indeed acting in self-defense and could dismiss all charges against Zimmerman.
If the judge denies his motion for immunity, a trial date will be set.
O’Mara asked the judge for a “complete sealing” of records entered in the case. Special prosecutor Angela Corey did not object and the judge agreed.
Earlier Thursday, Trayvon’s soft-spoken mother, Sybrina Fulton, called the slaying of her son “an accident” on morning TV and then had to clarify the statement.
Saying on NBC’s Today Show that she wanted an apology from Zimmerman, Fulton said, “I believe it was an accident. I believe it just got out of control and he couldn’t turn the clock back.”
Later, she issued a statement saying, “in NO way did I mean the shooting was an accident.
“We believe that George Zimmerman stalked my son and murdered him in cold blood. The ‘accident’ I was referring to was the fact that George Zimmerman and my son ever crossed paths. It was an accidental encounter.”
Trayvon was walking home from a 7-Eleven with a bag of Skittles in an Orlando-area gated community on a drizzly Sunday night when he was shot by Zimmerman, a 28-year-old volunteer neighborhood watchman.
Zimmerman followed the teenager even after cops told him to stop.
He said Trayvon jumped him and claimed self-defense under the Stand Your Ground law, which allows anyone who feels threatened to use deadly force.
Witnesses to the scuffle differ over who was the aggressor.
Several 911 calls included background audio of calls for help then a gunshot, but it is unclear who was yelling.
Asked if he planned to exploit Fulton’s comment, Zimmerman’s lawyer looked at a reporter with incredulity.
“They went through a horrible tragedy,” he said. “We’re not going to be talking about using words against the mother of a deceased child.”