See the video at post #61. Apparently, a "gate guard" at the truck stop had interacted with the "desperado", and had ascertained that it was a BB gun. And he told the police about it when they showed up.
BUT - since he didn't tell all 20 carloads of cops personally, it was lights out for the sleepy, headphone-wearing wino.
Fortunately, the peasants inside the truck stop managed to hit the deck when the unannounced fusillade began.