Paul Ciancia hadn't been seen in public since the Nov. 1 attack that created chaos at one of the nation's busiest airports and affected air travel around the country.
The 23-year-old spoke in whispers and showed no emotion during the 10-minute hearing in the West Valley Detention Center in Rancho Cucamonga, about 45 miles east of Los Angeles. He's being housed at the facility in federal custody.
U.S. Magistrate Judge David Bristow asked the diminutive, slender Ciancia if he understood the charges against him.
"Yes," responded Ciancia, who was shackled at his hands and feet and had a bandage on his neck and bruises on the left side of his face.
His lawyers didn't comment on his injuries.
Airport police responding to the rampage shot Ciancia four times, including once in the mouth. He was hospitalized for more than two weeks before being placed in federal custody.
The unemployed motorcycle mechanic did not enter a plea Wednesday to a murder charge that carries a possible death penalty if he's convicted.
Bristow determined Ciancia was a flight risk and posed a danger to the community, and ordered him to remain behind bars. The next hearing is scheduled for Dec. 18, but it could be waived if a grand jury indicts Ciancia.
Investigators said Ciancia walked into LAX's Terminal 3, pulled a semi-automatic rifle out of a duffel bag and fired at TSA Officer Gerardo Hernandez. An autopsy showed Hernandez, 39, was shot a dozen times.
Ciancia then fired on two other uniformed TSA employees and an airline passenger, who all were wounded, as he moved through the security checkpoint to the passenger gate area, authorities said. None of the three suffered life-threatening injuries.
Airport police shot Ciancia as panicked travelers either hid or fled.
Investigators have said Ciancia had a vendetta against the federal government and targeted TSA officers. His attorneys, who are both deputy federal public defenders, declined to discuss the case after the hearing.