'Boston bomber Dzhokhar Tsarnaev' has appeared in federal court in Boston Boston bombing suspect Dzhokhar Tsarnaev has pleaded not guilty on all charges relating to the attacks. Tsarnaev, 19, smiled crookedly - he appeared to have a jaw injury - at his sisters in court as he arrived. Then, after he leaned over toward a microphone and said, "Not guilty" over and over in a Russian accent, he was led out of the courtroom, making a kissing motion toward his family as he left. The proceedings lasted just seven minutes and took place in a courtroom packed with victims of the bombing, their families, police officers, and members of the public and the media. Tsarnaev faces 30 charges, including using a weapon of mass destruction to kill. The April 15 attack killed three people and wounded more than 260. Authorities say Tsarnaev orchestrated the attack along with his older brother, Tamerlan Tsarnaev, who died following a shootout with police three days after the bombing. "I just want to know why," said Liz Norden, whose two sons aged 32 and 33 each lost a leg in the attacks. This courtroom sketch depicts Boston Marathon bombing suspect Dzhokhar Tsarnaev during arraignment in federal court Wednesday, July 10, 2013 in Boston. The 19-year-old has been charged with using a weapon of mass destruction, and could face the death penalty. AP Photo/Margaret Small I just don't understand how you can live in this country and feel that way. Dzhokhar Tsarnaev was arrested on April 19 when he was found hiding in a boat in a suburban backyard. He was initially charged in the hospital, where he was recovering from wounds suffered in a police shootout. Tsarnaev's two sisters, both dressed in Muslim garb, were in court on Wednesday. One was carrying a baby, the other wiped away tears with a tissue. His parents remained back in Russia. Reporters and spectators began lining up for seats in the courtroom at 7:30am (9:30pm AEST) as a dozen Federal Protective Service officers and bomb-sniffing dogs surrounded the courthouse. Four hours before the hearing, the defendant arrived at the courthouse in a four-vehicle motorcade that included a van, a Humvee and a state police car. A group of about a dozen Tsarnaev supporters cheered as the motorcade arrived. The demonstrators yelled, "Justice for Jahar!" as Tsarnaev is known. One woman held a sign that said, "Free Jahar." This dramatic footage of the blasts at the finishing line of the Boston Marathon was captured from the viewing area across the street. Credit: YouTube/Ryan Hoyme. Lacey Buckley, 23, said she travelled from her home in Wenatchee, Washington state, to attend the arraignment. Ms Buckley said she has never met Tsarnaev but came because she believes he's innocent. I just think so many of his rights were violated. They almost murdered an unarmed kid in a boat," she said. A group of friends who were on the high school wrestling team with Tsarnaev at Cambridge Rindge and Latin waited in line outside the courtroom for hours, hoping to get a seat. One of them, Hank Alvarez, said Tsarnaev was calm, peaceful and apolitical in high school. "Just knowing him, it's hard for me to face the fact that he did it," said Mr Alvarez, 19, of Cambridge. Another ex-teammate, Shun Tsou, 20, of Cambridge, called Tsarnaev "a silent warrior type." MIT police officers stand at attention outside the federal courthouse prior to arraignment for Boston Marathon bombing suspect Dzhokhar Tsarnaev. MIT officer Sean Collier was killed by the alleged suspects. "There was nothing sketchy about him," said Mr Tsou, adding that he had not formed an opinion on Tsarnaev's guilt or innocence. Prosecutors say Tsarnaev, a Muslim, wrote about his motivations for the bombing on the inside walls and beams of the boat where he was captured. "I don't like killing innocent people," he said, but also wrote: "I can't stand to see such evil go unpunished. ... Three people - Martin Richard, 8; Krystle Marie Campbell, 29; and Lingzi Lu, 23 - were killed by the bombs, which were improvised from pressure cookers. Authorities say the Tsarnaevs also killed Massachusetts Institute of Technology officer Sean Collier days later while they were on the run. Numerous bombing victims had legs amputated after the two explosions, which detonated along the final stretch of the race a couple hours after the elite runners had finished. Duke La Touf, of Las Vegas, stands in support of Boston Marathon bombing suspect Dzhokhar Tsarnaev outside the federal courthouse prior to his arraignment. Jennifer Michio, left, from Mashantucket, Connecticut, and Duke La Touf, right, of Las Vegas, stand in support of Boston Marathon bombing suspect Dzhokhar Tsarnaev. This April 15, 2013 file photo shows medical workers aiding injured people at the finish line of the 2013 Boston Marathon in Boston following an explosion. Raw footage of the finish line at the Boston Marathon captures the bombings. Vision slowed.