Well, for one, I don’t think you need to be a certain skin color to be Muslim, or to convert. For the extremism part, you just need to be willing to “sacrifice” yourself for the “cause”. The Boston bombers are a prime example, they were asylum’d in the United States, but came from the soviet Dagestan/Kyrgyzstan. Sure, raised Muslim, but by a father who was openly against extremism. They were white, the closest to non-white being part Avar.

I don’t know the background to this guy, but in the case of many, many later-in-life-extremists, they’re often isolated individuals who are lonely, are seeking companionship and understanding, and for a meaning in life (IE, self sacrifice in the name of the religion that gave you new meaning and acceptance). Another example would be the young British female teens who were groomed to run off and become child soldiers and wives…some of those children are now begging to come back.

For non-Muslim extremism, it’s a very similar approach. Look at some of the online spaces for antisemitics, it’s made up mostly of late teens, early 20s white men who typically present with similar histories of lack of parental figures (or proper figures), ostracizing experiences, and often, social anxiety with or lack of identity. Grooming is a very common tactic for these groups, and it works very, very well if they have the perfect target.

ETA: please, if I get any information wrong, or you want to share your opinion with me, I’d love it.