And, as he sat in a spartan interrogation room in Hong Kong, he didn't really behave like one, either.
Suspects usually reacted to arrest in one of two ways, the now-retired agent told CNN from his home in New Jersey. Combative types embraced the machismo that helped them navigate the cutthroat world of drug dealing. Cooperative ones worried that not talking meant longer prison time. Tse didn't do either. He was calm, friendly and strategically tight-lipped -- even when Calnan told him the United States would be requesting his extradition.
Tse just smiled.
"He was impressive," said Calnan. "He was different."