Boston Marathon bomber Dzhokhar Tsarnaev returned to court Wednesday to be formally sentenced to death and listened as victims and their loved ones came forward one by one to berate him for his "cowardly" and "disgusting" acts.

"He can't possibly have had a soul to do such a horrible thing," said Karen Rand McWatters, who lost a leg in the attack and whose best friend, 29-year-old Krystle Campbell, was killed.

Krystle's mother, Patricia Campbell, was the first person to address the court. She looked across the room at Tsarnaev, seated about 20 feet away, and spoke directly to him.

"What you did to my daughter is disgusting," she said. "I don't know what to say to you. I think the jury did the right thing."

About 30 people were expected to speak at the sentencing in federal court. The outcome was a foregone conclusion: U.S. District Judge is required under law to impose the jury's death sentence for the April 15, 2013, attack that killed three people and wounded more than 260.

The big question was whether Tsarnaev would say anything when given a chance to speak. Tsarnaev, 21, has said almost nothing in court since his arrest more than two years ago, offering neither remorse nor explanation.

McWatters, Campbell's best friend, urged Tsarnaev to show remorse to discourage other jihadis from killing people in similar attacks.

"You can save them from these cowardly acts if you really have an ounce of regret or remorse," she said.

In May, a jury condemned Tsarnaev to die for joining his older brother, Tamerlan, in setting off the two pressure-cooker bombs near the finish line and in killing an MIT police officer as they fled. Tamerlan, 26, was killed during the getaway.

Tsarnaev wore a dark sport jacket with a collared shirt and no tie Wednesday. He appeared impassive as he chatted with his lawyers before the start of the hearing.

Bill Richard, whose 8-year-old son Martin was the youngest person killed in the bombing, said Tsarnaev could have backed out of the plot and reported his older brother to authorities.

Instead, Richard said, "He chose hate. He chose destruction. He chose death. This is all on him."

Tsarnaev, seated between his lawyers, looked down as Richard spoke.

Richard noted that his family would have preferred that Tsarnaev receive a life sentence so that he could have had "a lifetime to reconcile with himself what he did that day."

Richard said his family has chosen love, kindness and peace, adding: "That is what makes us different than him."

Tsarnaev's lawyers admitted he participated in the bombings but argued that Tamerlan was the driving force behind the attack.

In a note he scrawled in a boat he was found hiding in, Dzhokhar Tsarnaev said the attack was meant to retaliate against the U.S. for its actions in Muslim countries.