Should Colorado Shooter James Holmes’ Excessive Gun Purchases Caused Red Flags?

How can a civilian  purchase 4 guns (including an AR-15 Assault Rifle), 6000 rounds of ammo, a specialized drum magazine capable of holding 100 bullets at a time, bullet proof vest, bullet proof shin guards, bullet proof groin protector, and bullet proof throat protector within the last 90 days and not be red flagged by law enforcement? Especially since it …