Here's what we know about Fields:
1. A judge on Monday ordered Fields held without bond. The Toledo Blade reportedthat a judge denied Fields bail pending the appointment of an attorney.
The appearance lasted about 10 minutes, WJLA reported, with Fields responding only "yes sir," and "no sir." He did not enter a plea.
According to the Richmond Times-Dispatch, Charlottesville General District Judge Robert H. Downer Jr. told Fields that the public defender's office was unable to take him on as a client because a relative of one of the office's employees was injured in Saturday's crash.
The newspaper reported that lawyer Charles Weber was instead chosen from a list of possible court-appointed attorneys.
2. Fields reportedly told his mother, Samantha Bloom, that he was planning to attend the rally. According to the Toledo Blade, Bloom said Fields said he was going to an "alt-right" rally, but she didn't realize that it involved white supremacists.
"I thought it had something to do with [President Donald] Trump," Bloom told The Associated Press. "Trump's not a white supremacist."
She added: "He had an African-American friend, so ..."
Bloom told the Blade that she tries "to stay out of his political views."
3. The silver Dodge Challenger involved in the incident reportedly was registered to Fields and had a Lucas County tag. The Blade reported that Fields was found guilty of "having expired or unlawful license plates" on the vehicle in June.
4. Fields grew up in Kentucky but recently moved to northwest Ohio. The Bladereported that Bloom and her son moved from Florence, Kentucky, outside Cincinnati, to the Toledo area "about a year ago for her job." Fields moved out of her Monclova Township apartment to his own place in Maumee "five or six months ago," she told the Blade.
5. An uncle described Fields as "not really friendly, more subdued" in an interview with the Washington Post. Fields' single, paraplegic mother raised the boy after a drunken driver killed his father before he was born, the unnamed uncle said.
The uncle told the Post that Fields' father left money to his son, which was placed in a trust fund until Fields turned 18. The last time the uncle heard from his nephew was when Fields "demanded his money," the Post reported.
6. Bloom's neighbors in Monclova Township knew little about Fields. "I've never spoken with the gentleman; I don't know anything about him," one neighbor, Bob Rose, told the Blade. "You just never know. Until you get the whole story, you can assume what you want. Was he there to cause mayhem? Was he a white supremacist? I don't know."
The Blade reported that Fields frequently "blasted polka music" in his car when he was in the neighborhood, according to Laurie Schoonmaker, another neighbor.
7. A former teacher said Fields had "outlandish, very radical beliefs." According to CNN, Derek Weimer, a social studies teacher at Randall K. Cooper High School in Union, Kentucky, taught Fields during his junior and senior years.
"It was quite clear he had some really extreme views and maybe a little bit of anger behind them, feeling – what's the word I'm looking for? – oppressed or persecuted," Weimer said. "He really bought into this white supremacist thing. He was very big into Nazism. He really had a fondness for Adolf Hitler."
During Fields' freshman year, another teacher reported him to administrators over an assignment he had turned in, Weimer told the Cincinnati Enquirer.
"It was very much along the party lines of the neo-Nazi movement," Weimer told the Enquirer.
8. Fields served in the U.S. Army from August to December 2015. CNN reported that Fields did not meet training standards according to an Army spokeswoman.
"As a result, he was never awarded a military occupational skill, nor was he assigned to a unit outside of basic training," Lt. Col. Jennifer Johnson told CNN.
9. What's next? Fields, who is being held without bail at the Albermarle-Charlottesville County Regional Jail, will be in court for a bond hearing on Aug. 25, WJLA reported.