cause he's a retard, plain and simple
there's info on him at previous riots, too. apparently him and his brand of "boog bois" show up at these event in the name of anti govt. libertarianism, they try to rile up the other rioters to go hard after govt. property instead of private property because government bad.
obviously the nignogs don't give a fuck about any of that and usually simply ignore these clowns, but the hardline socialist antifa dudes at the riots get pissed and confrontational when someone spews ancap talking points at their riot and tries to shut down their anarchy orgy, so a confrontation was bound to happen eventually. at least lil boog over here was well-equipped and well-prepared for it, which is why he is alive and they are dead, but his shit is still fucked legally.
basically his explanation for getting involved boils down to "i wanted to join the riots because i hate the government, they're all faggots who violate the NAP! but then i saw other rioters violate the NAP by looting and burning someone's private property, so i had to intervene!" and i think everybody here can imagine how well this will sit with a judge and jury.