Derek Weimer, who taught history to Fields at Randall K. Cooper High School in Union, Kentucky, said he was a quiet, respectful student but had some "radical ideas on race."
"He was very infatuated with the Nazis, with Adolf Hitler. He also had a huge military history, especially with German military history and World War II. But, he was pretty infatuated with that stuff.
"In his freshman year, he had an issue with that that was raised, and from then on we knew that he had those issues. I developed a good rapport with him and used that rapport to constantly try to steer him away from those beliefs to show clear examples -- why that thinking is wrong, why their beliefs were evil, you know, things like that," Weimer said.
He said those views, combined with Fields' history of being prescribed antipsychotic medication, may have been a "perfect storm."
Warning: The video below contains language and images that may be disturbing to some viewers.
The vehicle that hit the crowd was purchased in June 2015 from a car dealership in Florence, according to a Carfax report. The vehicle’s registration was renewed in Maumee, Ohio in 2016, the report said.
The chaos boiled over at what is believed to be the largest group of white nationalists to come together in a decade: the governor declared a state of emergency, police dressed in riot gear ordered people out and helicopters circled overhead.
Oren Segal, who directs the Anti-Defamation League’s Center on Extremism, said multiple white power groups gathered in Charlottesville, including members of neo-Nazi organizations, racist skinheads and KKK factions. The white nationalist organizations Vanguard America and Identity Evropa; the Southern nationalist League of the South; the National Socialist Movement; the Traditionalist Workers Party; and the Fraternal Order of Alt Knights also were on hand, he said.
On the other side, anti-fascist demonstrators also gathered, but they generally aren’t organized like white nationalist factions, said Heidi Beirich of the Southern Poverty Law Center.
In addition to Fields, at least three more men were arrested in connection to the protests.
The Virginia State Police announced late Saturday that Troy Dunigan, a 21-year-old from Chattanooga, Tennessee, was charged with disorderly conduct; Jacob L. Smith, a 21-year-old from Louisa, Virginia, was charged with assault and battery; and James M. O’Brien, 44, of Gainesville, Florida, was charged with carrying a concealed handgun.
Robby E. Noll, who lives in the county just outside Charlottesville, heard the helicopter sputtering.
"I turned my head to the sky. You could tell he was struggling to try to get control of it," he said.
He said pieces of the helicopter started to break off as it fell from the sky.
Both troopers onboard, Lt. H. Jay Cullen, 48, and Berke M.M. Bates, one day shy of his 41st birthday, were killed. Police said the helicopter had been deployed to the violent protests in the city, which has been caught in the middle of the nation’s culture wars since it decided earlier this year to remove a statue of Confederate Gen. Robert E. Lee, enshrined in bronze on horseback in the city's Emancipation Park.
In May, a torch-wielding group that included prominent white nationalist Richard Spencer gathered around the statue for a nighttime protest. That scene replayed Friday night, when white supremacists marched through the University of Virginia campus chanting "blood and soil," a Nazi slogan.
In July, about 50 members of a North Carolina-based KKK group traveled to Charlottesville for a rally.
Spencer returned for Saturday's protest, and denied all responsibility for the violence. He blamed the police.
Signer said the white supremacist groups who came into his city to spread hate "are on the losing side of history."
"Tomorrow will come and we will emerge," he said, "I can promise you, stronger than ever."