A federal judge imposed a life sentence on the self-described neo-Nazi who killed Heather Heyer by crashing his car into a crowd of counterprotesters in Charlottesville, Va., after a white supremacist rally, saying release would be "too great a risk."

The 22-year-old neo-Nazi, James Fields of Maumee, Ohio, was sentenced to life without the possibility of parole. He had sought a lesser sentence, apologizing after the court viewed video of him plowing his car into a crowd after the Aug. 12, 2017, "Unite the Right" rally, also injuring 19 people.

U.S. District Judge Michael Urbanski, was unmoved by his plea, saying he had had to avert his eyes while the court viewed graphic video of the attack that showed bodies flying into the air as Fields crashed into them.

"Just watching them is terrifying," Urbanski said. "The release of the defendant into a free society is too great a risk."

The rally proved a critical moment in the rise of the "alt-right," a loose alignment of fringe groups centered on white nationalism and emboldened by President Donald Trump's 2016 election.

Trump was criticized from the left and right for initially saying there were "fine people on both sides" of the dispute between neo-Nazis and their opponents at the rally. Subsequent alt-right gatherings failed to draw crowds the size of the Charlottesville rally.

Heyer's parents described the grief of losing their daughter.

"It was an incident I will never fully recover from," said Heyer's father, Mark Heyer.

Her mother, Susan Bro, described herself as "deeply wounded" and recounted crying uncontrollably at times.

Ahead of Friday's sentencing hearing, prosecutors noted that Fields had long espoused violent beliefs. Less than a month before the attack he posted an image on Instagram showing a car plowing through a crowd of people captioned: "you have the right to protest but I'm late for work."

Even after the attack, Fields remained unrepentant, prosecutors said, noting that in a Dec. 7, 2017, phone call from jail with his mother, he blasted Bro for her activism after the attack.

"She is a communist. An anti-white liberal," Fields said, according to court papers filed by prosecutors. He rejected his mother's plea to consider that the woman had "lost her daughter," replying, "She's the enemy."

Fields pleaded guilty to the federal hate crime charges in March under a deal with prosecutors, who agreed not to seek the death penalty.

He was photographed hours before the attack carrying a shield with the emblem of a far-right hate group. He has identified himself as a neo-Nazi.

Fields' attorneys suggested he felt intimidated and acted to protect himself. They asked for mercy, citing his relative youth and history of mental health diagnoses.