Scott Beierle spewed misogynistic and racist hate online in a series of YouTube videos.
Some believe the 40-year-old may have carried out the attack as an act of revenge on women for rejecting his romantic advances.
In one of his YouTube videos he sympathized with Elliot Rodger, a self-described "Incel” which stands for "involuntarily celibate." The 22-year-old murdered multiple people near the University of California, Santa Barbara, in 2014 before turning the gun on himself.
The shooting in Tallahassee is the third deadly attack this year in which Rodger has been praised by an assailant.
In April, the man accused of mowing down 25 people in Toronto, killing 10, idolized Rodger and also called himself an “Incel.”
Another admirer of Rodger was Nikolas Cruz, the social misfit charged with carrying out the Parkland school massacre on Valentine’s Day.
There's an estimated 40,000 other “Incels” out there and the number is growing, according to those knowledgeable about the subject.
Judith Taylor is an expert on the "Incel" phenomenon.
“This is a very scary movement,” she told Inside Edition. “It's leaderless and it really takes its power from the internet. It really collects people who feel socially dislocated and it gives them scripts to follow."
Taylor says violence by “Incels” is happening at an alarming rate.
“This is mainstreaming of hatred and so we really have to crack down on this if we don't want to see some sort of civil war against women," she said.