CHATTANOOGA, Tenn. — The room was quiet and sparsely filled when Johnthony Walker entered.

The 24-year-old made his first court appearance Tuesday morning, a week after a school bus he was driving in Chattanooga crashed, killing six children and injuring even more, authorities said.

Dreadlocked hair drawn back, wrists cinched together, Walker appeared calm in a red jumpsuit as he quietly addressed Judge Lila Statom in Hamilton County Criminal Sessions Court, a private lawyer at his side. Defense attorney Amanda B. Dunn requested a continuation to Dec. 15. Hamilton County District Attorney General Neal Pinkston agreed to it, as did Statom.

“I'm going to block off my docket that morning,” Statom told Walker.

Walker faces five counts of vehicular homicide and one count each of reckless endangerment and reckless driving. Police have said they plan to seek additional charges, including a sixth count of vehicular homicide.

Dunn wanted more time because police have been able to provide her only limited information, according to the district attorney's office.

“Due to the nature of the crash, investigators have had a more difficult time than normal retrieving data from the recording devices recovered from the bus,” said Melydia Clewell, spokeswoman for the district attorney. The National Transportation Safety Board and local authorities are investigating the crash.

Reporters, photographers and television crews lined the courtroom's back row. A dozen or so onlookers sat on the remaining benches. It was unclear whether any were friends or family of the victims or Walker. Two declined to comment when approached after the hearing, which lasted no more than 15 minutes.

Outside the courtroom, Dunn acknowledged the tragedy and its collective pain, but noted that Walker had not yet been found guilty.

"Mr. Walker's family is also devastated by this tragedy. Mr. Walker is devastated,” Dunn said. “As he sits in the jail now, Mr. Walker is an innocent man. In the eyes of the law, he will remain so until proven (otherwise).”

Walker is being held in protective custody in the Hamilton County Jail.

“Apparently other inmates have threatened to kill him,” Clewell said.

His total bond for all seven charges is $107,500.

At the Dec. 15 hearing, Walker can ask for another continuation, plead guilty to the charges, or he can waive his right to the hearing, which would automatically send the case to a grand jury. He also can choose to have the hearing, during which he's allowed to testify on his own behalf and call his own witnesses.

The prosecutor is required only to provide enough evidence to show reasonable cause for the case to go to a grand jury.

The school bus crash happened at the start of what's typically a happy holiday week. School and work end early for most, heralding a holiday built on gratitude and family. But on Nov. 21, the Monday afternoon before Thanksgiving, one bus ride home from Woodmore Elementary School ended with most of its young passengers injured or worse.

According to police, Walker was driving at a “high speed” on a narrow winding road, “well above the posted speed limit of 30 mph.” He lost control of the bus and it swerved off the road, hitting an elevated driveway and mailbox before flipping over and crashing into a utility pole and tree.

More than 20 of the 37 students on board were injured, some critically. Six students died: 10-year-old Zyanna Janal Harris, 9-year-old Cor'Dayja Jones, 9-year-old Zoie Nash, 8-year-old Keontae Wilson, 6-year-old D'Myunn Brown and 6-year-old Zyaira Mateen.

The 2008 bus didn't have seat belts. Records released by the local school district last week showed that schoolchildren had complained in the past about Walker's driving, saying it was too fast and that he made sharp turns. Meanwhile, Walker had told administrators that students wouldn't listen to him when he told them not to stand in the bus and not to sit with their backs facing the front.

This wasn't Walker's first accident with a school bus. In September, he sideswiped a Kia Soul trying to get around a curve, according to the Chattanooga Police Department. No one was injured, there was only minor damage, and neither drugs nor alcohol appeared to have been a factor. Walker was not cited, but he was found to be at fault.

“That type of wreck is considered minor so the insurance companies typically handle how things proceed,” police spokeswoman Elisa Myzal said.

The private company that owned the bus has had 142 crashes with injuries and three fatalities in the past two years, according to the Federal Motor Carrier Safety Administration. Durham School Services, which operates thousands of school buses in several states, got a “satisfactory” rating, but it also lags behind its peers for on-road performance.

Shortly after the Chattanooga crash, the Illinois-based company's CEO posted a video message on the company's main webpage, his voice cracking as he pledged to take steps to ensure nothing like the accident happens again.

“I can't fathom the anguish of the parents whose children were involved in this horrific accident and that involved one of my company's buses,” David A. Duke said. “Nothing that I can say can take away the pain and the grief.”