If it turns out that Kam and Bryer acquired the weaponry by underground methods, false name and address stuff, ordering with false ID, delivered to a pre arranged address, that would point to a certain degree of premeditation, would it not? . At the very least, a plan to be shooting at stuff, things, beings, perhaps people.
Maybe they had to order the ammo along with the guns, and they just didn't order enough, .. or they did, and did a whole lot of practice stuff before heading north... again, a certain degree of pre meditation going on there. ..
And then took off, rather quickly, left the job at Walmart suddenly, by all accounts, without re ordering the ammunition. ..