Dzhokhar Tsarnaev shuffled into the courtroom, appearing confident despite the ankle chains and an orange jumpsuit so big on him that it made him appear younger than his 19 years.
As federal prosecutors read the charges against him Wednesday in his first appearance since being captured in April, Tsarnaev repeatedly looked over his shoulder at the packed courtroom, at one point blowing a kiss to his sisters, one sobbing and another holding a baby.
He leaned into the microphone in the hushed courtroom to tell Judge Marianne B. Bowler with an accent that he pleaded not guilty to 30 charges, including use of weapons of mass destruction. More than 30 victims of the Marathon bombings and about a dozen supporters who say they believe Tsarnaev is innocent watched intently as the accused terrorist yawned and stroked the side of his face, which appeared swollen from a wound.
Tsarnaev, who could receive the death penalty, fidgeted in his seat as he listened to the charges, one of his attorneys patting him on the back gently several times. He had a visible scar just below his throat and had a cast on his left arm.
Jennifer Regan of Stoneham — fiancee of Marc Fucarile, who lost a leg in the bombing and remains at Spaulding Rehabilitation Hospital — summed up her feelings at finally seeing the alleged bomber: “He’s disgusting,” she said.
Assistant US Attorney William Weinreb read the charges out loud, saying, “The maximum penalty is up to life in prison or the death penalty.”
Because the case is in federal court, US Attorney General Eric Holder will decide whether Tsarnaev should face the death penalty, which has not been administered in Massachusetts in 66 years.
Tsarnaev’s appearance lasted about seven minutes and was under heavy guard. His older brother, Tamerlan, the alleged mastermind of the bombings, died after a confrontation with police in Watertown.
For weeks, the John Joseph Moakley US Courthouse has been the venue for one of the biggest criminal trials in the past decade in Boston, the racketeering case against Boston gangster James “Whitey’’ Bulger. On Wednesday, however, most of the attention was on the slight former University of Massachusetts Dartmouth student who had emigrated from Russia.
Outside the courthouse, lines of uniformed MIT police officers stood at attention, honoring Sean Collier, the young officer who was allegedly shot to death in his cruiser by Tsarnaev.
MIT Police Chief John DiFava walked from the courtroom, saying the defendant is “not worth a tear.”
“I’d like to grab him by the throat,’’ he said.
Before the proceeding, about a dozen supporters of Tsarnaev cheered as heavily armed US marshals escorted the defendant’s motorcade to a back door.
They held signs calling for him to be exonerated and chanted “Justice for Dzhokhar’’ and “Give him his freedom back.”
Their shouts enraged a man who was walking past the courthouse.
“You are disgusting. You’re disgusting,’’ said the man, who would not give his name. “Don’t you know people died?’’
Several members of the high school wrestling team that Tsarnaev captained during his senior year at Cambridge Rindge and Latin School also came to see their old friend.
“What they say he did is a big question mark to me,” said Shun Tsou, 20. “He was just a regular guy. He cracked jokes.”
Their coach, Peter Payack, watched proceedings on closed-circuit television in a separate courtroom, an experience he called “heart-wrenching.”
“I was looking to see if I could see any remorse, but I couldn’t tell,” he said.
Payack and some wrestlers said Tsarnaev’s “not guilty” answers seemed to reflect a foreign accent, which is not how they recall him speaking.
The indictment alleges that before the bombings Tsarnaev downloaded extremist Islamic propaganda from the Internet, including material directing Muslims not to give allegiance to governments that invade Muslim lands and writings by Anwar al-Awlaki, the American citizen who became a senior operative in Al Qaeda’s branch in Yemen and who was killed in a 2011 drone strike.
Tsarnaev allegedly wrote a confession in the boat where he hid from authorities until emerging covered in blood in a Watertown backyard.
The note reportedly justified the violence because the “US government is killing our innocent civilians” in other countries.
“I can’t stand to see such evil go unpunished,” he allegedly wrote. “We Muslims are one body.”
The federal charges include malicious destruction of property resulting in death, conspiracy, use of a firearm during a violent crime, and carjacking resulting in serious injury, federal prosecutors said.
After the arraignment, Tsarnaev was escorted by deputies from the US Marshals Service back to a locked medical facility for male prisoners at Fort Devens, where he has been detained since being released from Beth Israel Deaconess Medical Center.
Many of the victims avoided the large presence of news crews swarming around the heavily guarded courthouse.
Others said they want to ensure that their pain is not forgotten.
Mildred Valverde, 44, of Somerville went to Boylston Street to watch her son’s former teacher run the Marathon and suffered ligament, muscle, and nerve damage, as well as vision loss from the blast.
She came out of court using one crutch and wearing an ankle boot. Her 15-year-old son suffered a concussion and emotional distress.
She said she attended the arraignment “to show my son that life goes on, [to] be strong in the face of everything.”
She said seeing Tsarnaev, whose dark eyes never gazed back at the side where many victims were seated, didn’t change anything for her.
“I want him to rot in jail for the rest of his life and suffer the way he’s made many other people suffer,” she said.
Tsarnaev has a status hearing scheduled for Sept. 23.
Patricia Wen, Michael Rezendes, and John R. Ellement of the Globe staff and correspondent Haven Orecchio-Egresitz contributed to this report. David Abel can be reached at email@example.com. Follow him on Twitter @davabel. Eric Moskowitz can be reached at emoscowitz@
globe.com. Follow him on Twitter @globemoskowitz.