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You're coming out of this car one way or the other, and we're going to search this car. Take a look, a Valley preacher says he took a beating at a Border Patrol checkpoint. But that he did nothing wrong. CBS 5's Steve Filmer is live with more on this man's story. Steve? Yeah, anybody traveling back along Interstate 8 from California or Yuma will know this Border Patrol checkpoint that's involved in this incident. It is not, though, actually on the border with Mexico. Broken glass comes flying at me from both sides, and instantly I'm tased from both sides. His story is vivid, his clothes still stained with blood. Blood Stephen Anderson says poured out of his head and face as he was roughed up by a DPS officer and Border Patrol agents. I'm sitting here like this, crying for mercy, screaming. Next thing I know, an agent takes my head and shoves it into the broken glass on the side of the window where he had just broken out the window. I can feel the glass shoving into my scalp, and then I'm thrown on the ground next. They're still tasing me throughout this. Anderson is a preacher at this small Baptist church in Tempe. He says he was stopped at the Border Patrol checkpoint on Interstate 8 Wednesday night. He was riding back to the Valley from San Diego. They slow us down, everybody goes through the checkpoint. They walk up to the window, begin to ask me questions. Where are you headed? I didn't answer any questions. They asked me if I'm a U.S. citizen. I wasn't answering any of their questions, and I was just asking, can I please just go, I just want to go home. He's told to pull aside. An hour goes by while he sits in his car. DPS arrives to tell him he's under arrest. He said, our dog alert us that you either have a human being or drugs in this trunk. Anderson insists he doesn't have to submit to the search. That, he says, leads to the officer's breaking windows, firing tasers. I was the one that I had trouble pulling out. Then humiliating him while he's in handcuffs. And they're laughing at me, oh, you're not so tough now. You didn't think we were going to search you, huh? And they're laughing at me, they're razzing me, and it's all on those Border Patrol surveillance tapes. Of course, we are pushing both of these agencies for hard facts about their side of the story. First, with DPS, a spokesman there with DPS tells us, we are investigating our officer's actions. You should also check with the Border Patrol. The Border Patrol spokesman confirms that Anderson was asked to pull aside for an inspection after a search dog alerted to assent from his vehicle. And then that DPS was called to take over the situation after Anderson stayed in the regular traffic lane for about an hour and that DPS ultimately took him into custody. The Border Patrol also adds that they do not use tasers as part of their nonlethal arsenal. Reporting live in downtown Phoenix, I'm Steve Filmer, CBS 5 News.