but many afghans maintain that the us military made a mistake and that mohammed amin is someone else entirely from the man they killed that day. michael semple, a former un official and now a visiting fellow at harvard, is one of the leading experts on the taliban. he has lived and worked in the region for 20 years. semple says he has tracked down and met the taliban commander mohammad amin in person, after the attack that was supposed to have killed him. >> mohammad amin is alive. he's somebody who did indeed serve as a deputy governor for the taliban system in takhar who's been engaged in the insurgency, somebody who we can place. but the point is, he's flesh and blood. he's real. he's got an identity that can be checked out-- and that we have checked out-- and he's still alive. >> narrator: the military remains convinced they killed the right man. a us official with direct knowledge of the operation told frontline:" the evidence, from multiple sources, is overwhelming. we know that this man was ordering attacks, and we know that, after the strike insurgents themselves were saying