Emotions ran high Thursday in death penalty proceedings for a man convicted of killing eight people on a New York City bike path, as the man’s father professed both shame and love for his son and the defendant’s uncle shouted "dirty ISIS bastards!" and punched a door as he left the room.

Habibulloh Saipov’s testimony in Manhattan federal court and the subsequent outburst came in front of a jury that must decide whether Sayfullo Saipov gets death or life in prison for the Halloween day attack in 2017, when he drove a truck along the busy path near the World Trade Center memorial, mowing down pedestrians and cyclists.

"I'm sorry that this has occurred," Judge Vernon S. Broderick said after the jury left the room. He expressed concern at the effect the dramatic turn might have on jurors and warned defense lawyers to ensure there was no repeat of such behavior. Testimony did not resume for two hours.

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"That we’re disappointed at that is an understatement," lawyer David Patton told the judge. Broderick later banned the uncle from the courthouse.

The death penalty phase began after the same jury last month convicted Sayfullo Saipov, 35, who throughout the trial has slumped in his chair and appeared unrepentant and unemotional.

But he perked up as his father, whom he only recently saw for the first time in 13 years, took the stand to decry the terror attack, saying it has left the family ashamed.

When asked by defense attorney David Stern how he reacted to his son’s attack, Habibulloh Saipov said: "My soul was destroyed."

"He committed a terrible tragedy. He caused death for eight people and injuries for many more and he ruined their lives," Saipov said.

"How do you feel about what he did?" Stern asked.

"I feel very bad about this. And I would like to apologize in front of everyone, all victims," he continued.

Habibulloh Saipov testified that he once told his son after working in the United States for five years that "people there are sincere and they are always smiling to each other."

When the son came to the country in 2010 and began working as a truck driver, the father said they frequently had hourslong conversations to keep him awake on long hauls.

Habibulloh Saipov cried as he recounted learning that his son had carried out the attack and seeing his wife collapse and faint after seeing images of the aftermath on her phone. He said he was then subjected to 15 days of interrogation by law enforcement.

At one point, Sayfullo Saipov pulled his coronavirus mask away from his face to wipe around his eyes as his father cried.

The father also told of phone calls in which Sayfullo Saipov bragged that he should feel lucky to have a son who had done something heroic.

"Do you feel lucky to have a son who did what he did?" Stern asked.

"No, not at all," the father answered.

Habibulloh Saipov acknowledged that he’ll likely never see his son again after he returns to his country, Uzbekistan, on Friday.

Asked if he still loves him, he said, "With all my heart."

He added that he hopes his son is spared the death penalty so he’ll realize the truth about his crimes.

The outburst from the uncle and another shout from an unidentified woman left a family member of one victim sobbing as the judge summoned a nurse. He also directed that Sayfullo Saipov be checked.

The words "dirty ISIS bastards" were relayed by an interpreter at the judge's request. The interpreter said whatever else was said by anyone was unintelligible.

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Sayfullo Saipov told investigators following his arrest that he carried out the killings after the Islamic State group called for terror attacks.

Testimony resumed after a long break, and the judge instructed jurors that the uncle's outburst was not directed at the court, jury, prosecutors, defense or trial process.

Hamidulloh Saipov, another uncle, testified that he too still loves his nephew, though he believes he did "something wrong, something unbelievable."

"He broke everybody’s hearts. He broke our heart," the uncle said. "Everybody was shocked. Everybody was sick."

He said Sayfullo Saipov had changed due to being "influenced by bad people" and added that he hopes his nephew "will get back to himself."

Sayfullo Saipov's sister, a year younger than him, finished the day's testimony with a tearful description of the damage her brother's actions have done to their parent's health.