4chan is ephemeral (posts are routinely culled) and supposedly anonymous (the default name setting for anyone posting is simply “Anonymous”). However, the website inserts a unique string of letters and numbers that stick with each person in any one thread—as a way of keeping track of who’s who in a conversation, while maintaining the veneer of anonymity.This meant that, using the 4chan archiving site 4plebs.org, I was able to track @thereal_JacobK’s other comments in the thread, revealing hitherto unknown details about his life, including his frustration with living in Germany, his desire to move to the US, and his love for the Second Amendment. But perhaps most strikingly, he described himself as an incel—the term used by the misogynistic online community who define themselves as “involuntary celibates.”Revealing the Personality Behind the GunThe way Jacob D wrote, anonymously, in that 4chan thread was also revealing. He only capitalized the word “I” at the start of a sentence—never after that. And he always inserted a space before an exclamation or question mark, which isn’t typical for Germans.Analyzing these writing habits is the domain of forensic linguistics, made famous for its use in the arrest of the Unabomber, Ted Kaczynski. These stylistic features meant I could track more of his comments in other conversation threads—with his repeat use of the same images sometimes giving an extra clue to threads he had been in.Eventually, I discovered threads in which Jacob D had uploaded photos of himself, including one where he showed his face. In part by using a facial recognition platform, I was then able to discover his old SoundCloud and Couchsurfing profiles—in the latter, he said he planned to travel to the US, “the country which fascinated me since my teens,” before he joined the German military.And in both of these profiles, he revealed his real name: Jakob Duygu.Ultimately, I have been able to track hundreds of supposedly anonymous posts that Duygu posted on 4chan and other message boards over the years. The FGC-9’s designer wrote about his life in Germany, his time in the Bundeswehr (German armed forces), and his loneliness and despair at being an incel. They show him as a complex, volatile, obsessive, and tragic person. And they also reveal some extremist ideas.The difference between these comments and those he made publicly in interviews (using his JStark1809 pseudonym) was striking. In interviews, he spoke about the need to protect free speech and human rights. He invoked the example of the genocide of European Jews in the Holocaust or the Uyghur people in China as arguments for why people need to have firearms, and why he created the FGC-9.But when you look at his anonymous comments, a different picture emerges. Far from being a person concerned about human rights, his words were often xenophobic, racist, and antisemitic. And this wasn’t exclusive to 4chan, which has a particularly offensive, obnoxious culture where perhaps not everything should be taken at face value.