https://en.wikipedia.org/wiki/FGC-9

>Jake Hanrahan of Popular Front interviewed JStark1809 about the FGC-9 and 3D printed guns in November 2020.[26] JStark1809 stated that he had no background in engineering, taught himself CAD, and learned what he needed through widely-available resources on the internet. With his rudimentary operation, he showed how to manufacture an FGC-9 in two weeks or less. He shot the gun in a forest and demonstrated its reliability and rapid firing rate. JStark1809 described his absolutist belief in the right to keep and make arms, as well as his desire to make the weapons widely available in order to protect human rights. Hanrahan described him as "one of the most dangerous people" he had ever met and criticized authorities for underestimating the power of 3D-printed guns.[26]

>Der Spiegel reported in October 2021 that British financial services had provided clues on the identity of JStark1809 to the Federal Criminal Police Office, and they identified a 28-year-old man in Völklingen who went by "Jacob D." Police had raided his home that June, though they found no weapons and did not take him into custody. Two days after the raid, he was found dead in his car in front of his parents' home in Hannover. Coroners determined the cause of death to be a heart attack and ruled out foul play.[3]

https://icsr.info/wp-content/uploads/2023/10/ICSR-Report-Behind-the-Mask-Uncovering-the-Extremist-Messages-of-a-3D%E2%80%91Printed-Gun-Designer.pdf

>JStark’s “anonymous” comments reveal his life as an incel (involuntarily celibate). He felt his autism, height, looks, and ethnicity would shatter
his chances of having a sexual or romantic relationship in Germany.

>In 2018, he travelled to the Philippines to escape his life as an incel.

>He regularly made misogynist comments. He sometimes revelled in female suffering and despaired at his lack of relative power. He varied between condoning incel-motivated violence and seeing it as inevitable. Shortly before his arrest in June 2021, he threatened violence: “I will literally kill , (sic) or kill myself soon if i can’t sleep in a bed with a girl again …”.