Wondering if he was one of the nutty "Anarchoqueers" (their name, not mine) who hate Pride because it's "Capitalist" and "Homonormative". The hardcore OWS types have a history of planning terrorist attacks that get foiled because they're really bad at this, like the planned bridge bombings.
It's more likely that this was a bisexual dude who just loved guns and drugs. And on his way to LA Pride he was stopped by the cops, while he was under influence of some of those drugs, and they ask where he was on his way. So the cops stop a White derange dude in a car with a lots of weapons on his way to LA Pride just after the terror attack on a gay club in Orlando. I know how I would react, and the police reacted the same way.