This is supposedly the meme (or one of the memes?) that resulted in the "investigation" that led to his arrest and incarceration pending his (bail) hearing on September 6:

Here's more from the article at
https://news.unclesamsmisguidedchildren.com/sharing-memes-man-ends-up-red-flagged/SHARING MEMES – MAN ENDS UP RED FLAGGED“Boogaloo” – a slang term for shit-hits-the-fan, or government gone bad and they’re coming for you, time to fight back. Boogaloo toys refers to guns. The opposite of “bugging out.”
“Alphabet bois” – ATF, FBI, DEA, etc.
“Coat hanger sears” – hand-crafted drop-in auto sears for an AR.
Wagshol has been banned from the campus of the college he was attending. The media is calling this
a ‘mass murder plot foiled.’ But was it really?
A Boogaloo meme is not about mass murder, it’s about defending yourself from the government.Instagram has blacklisted any reference to the word “boogaloo.” Big Tech appears to feel that such memes are dangerous and need to be banned.
* * * * *
I'm not claiming the guy is NOT mentally unstable and likely to commit violence, only that the apparent evidence of that is minimal (or possibly laughable). Only a team of
"objective" (haha) "mental health professionals"
might be able to determine that. But until then, posting such memes as above would seem to be the oft-laughed-at and ridiculed (by leftist socialist civilian disarmament advocates) "slippery slope" in action.