“Right now, my money’s on white suburban punk anarchists.”
Very likely true.
But, just as likely is that the supplies ,funding, motivation, and encouragement is coming from terrorists who flee just prior to the planned attack.
Hence, the link between the two stories.
My guess the day after was
90% Leftwing anti-war types
9% Islamic terrorists
1% someone trying to keep the terror issue in the forefront
now it’s 51% category A and 49% category B