A 17-year old white supremacist killer loose in the streets with an assault rifle isn’t just born; he has to be made. It’s not nature, it’s nurture.
Some or all of the following features also have to be in place:
Parents and other family members and caregivers who are racist and who encourage the use of weapons OR who are in the dark about their child’s activities OR are unable to do anything about it or get any help regarding it.
Media groups and social media groups promoting white racism and who directly or indirectly in various degrees advocate that it’s okay and even good for white people to take up weapons against non-white people. Decades of such media groups have helped raise new generations of violent white supremacists.
Racist neighbors who often share around the neighborhood their attitudes and the information they have heard on media supporting those attitudes.
Easy availability and access to high-powered weaponry for private citizens.
A peer group of others who encourage each other and share behaviors and attitudes. It never hurts to have a few good pals egging you on to kill people! One of the great things about social media is that it helps people find like-minded others.
People in positions of prominence in business and government and news who passively or actively encourage racist hate. It never hurts to have power on your side, and if that includes the President of the U.S. and a prominent political party, how cool is that?!
Police forces on the streets who see a young white man on the streets with a rifle and immediately identify him as someone on their side.
Higher ups in law enforcement who themselves might be actively involved in white supremacy or who encourage it through their actions or speak up in ways that seem to support it.
A minor who is just twisted and abandoned or coddled enough to actually follow through on what many people around him have encouraged him to do and try to make himself a hero by killing people who have done nothing to him or to anyone he knows.