"Subject was last seen engaging in disorderly conduct and physical harassment of White Europeans," the poster read.
It also stated that she was "well known for hysterically screaming at complete strangers in public places."
Spencer denied having any involvement in the posters.
"I haven't seen anything like that," he told BuzzFeed News via text message.
He also denied any knowledge of the group named on the signs, Blood and Soil. "I've never heard of that group," he said.
Some of the racist posters seen in Alexandria are available for download on the extremist group's website.
Professor Fair told BuzzFeed News that she was not intimated by the posters.
"They made a really huge strategic overstep, because any sympathy they got that their Nazi bro couldn't lift in his gym, this actually exposes their true colors," she said.
Fair said she had been contacted by police, who she said were investigating it as a hate crime.
"[Police are] collecting them and they're fingerprinting them and we've got cameras, so it looks like we're gonna know who the dude is," she said.
Fair said she was used to being targeted by right-wing trolls.
"I know how these stupid idiots work," she said. "They have ordered pizza to my home. They have applied to online jobs for me.
"This is the kind of chicanery that spoiled rotten 12-year-old boys do when they don't have a decent babysitter," she said.