His mother told local media that he did not openly express extreme views.
But evidence is emerging of a “very misguided and disillusioned” young man.
Mr Fields’ former teacher characterised him as such to the Cinnicinati Tribune, and said his high school research made it clear he had beliefs that were “very much along the lines of the neo-Nazi movement”.
“A lot of boys get interested in the Germans and Nazis because they’re interested in World War II. But James took it to another level.”
After enlisting in the military, Mr Fields was released in December 2015 for “failing to make training” standards.
It also had a photograph of the 20-year-old posing with a car resembling the one used in the attack and a variety of memes popular with the alt-right, including Pepe the Frog.
Buzzfeed also posted Youtube footage appearing to show Mr Fields chanting homophobic slurs at counter-protesters at the “Unite the Right” rally hours before the attack.
He was pictured at the event (second from left) carrying a shield with the logo of an openly fascist group: Vanguard America.
The group’s website declares “America is under attack” and says: “If current trends continue, White Americans will be a minority in the nation they built. It’s time to take a stand.”
They released a statement on Twitter denying James Fields had been a member.
He has been charged with one count of second degree murder, three counts of malicious wounding and one count of failing to stop after a hit and run.