That really just makes him an easy fall guy.

Like, affluent enough to have the free time, visibly disillusioned with the system, on pain management from a back injury, similar hoodie/ backpack style of dress day to day.

Like, this is a big enough problem that there is an incentive to pick a random person of interest out of a hat and fabricate some quick evidence to implicate. Was the gun found in the manifesto bag the same gun that shot the guy?