Your .02 isn't worth a plug nickel in this instance. It's not at all appropriate to turn this into a terrorist hunt, because there's no evidence to favor that conclusion over a variety of other explanations. It would be stupid to rule out nutjobs, neo-nazis, anarchists, disgruntled cops or ex-soldiers, or a variety of other possible explanations.
Maybe a cop that was overlooked for a promotion, when Moose was hired? Someone leaked the tarot card. Trying to make Moose look bad.