"Asian" or "Asian American?"

My friend over at Poplicks made this observation that he picked up over at Angry Asian Man. The shooter was Seung-Hui Cho, a senior majoring in English from South Korea. From the numerous reports, he is a legal resident of the US and his family resides in Centerville, VA. Now here's where it gets a bit dodgy ... He's 23 years old, but documents indicate he was living in the US since 1992. That's 15 years ago. That means he's been socialized as an "American kid" since he would've been 8 years old at the time he arrived to the US. So why are news agencies still calling him, seemingly at great lengths, a "legal immigrant" or a "resident alien?" Technically, he's "Asian American" or in Asian American Studies terms, he fits the classic 1.5 generation: foreign born, but raised in the US. There's very little to suggest that he's "foreign" in the recent immigrant sense of the term. He's just as American as the next kid. So what gives???