He was secretive until he wasn't. The Coast Guard flagged him because of internet searches of extremist web sites at work. It was fortunate for many people that he F$%#ked up. Most of the terrorists in the U.S. appear to be white men with some kind of a grudge. trump's stupid wall won't do shit for that problem ... no matter how much trump's lies about it. trump's been uncharacteristically quiet about this guy though. Hmm! I wonder why? I guess it doesn't fit trump's agenda.
I've heard this but you won't find that message coming out of the Trump camp. This might be because they will find the man was a big Trump supporter. The original report of what he wanted to do has now been changed to how he was trying "to figure out how to kill all of mankind." This change can only be to protect Trump and his supporters. Hate crimes are on the rise by close to 30% in the last 2 years because Trump cannot go against his base and take a stand on the issue. Remember that he thought "both sides" were right in Charlottesville.
There are also a few rabid Christians who want to end all of mankind because they think it will let Jesus come again.