newspaper, morten storm, a danish convert to islam, says he went to yemen and worked with the cia to help track and kill al awlaki. >> he was a terrorist. he wanted to kill innocent people. >> reporter: storm was part of a radical islamic group in europe. this was him in '05 at an anti-u.s. rally that made news in london. six months later, he says, he had been recruited by danish intelligence for his dangerous role. >> if al qaeda had come to the conclusion that he was spying for the danes and the cia, they would have killed him immediately. >> reporter: in fact, like popular "homeland" tv show, agents use high-tech devices to track their targets. >> start with the encrypted files. really, it's important. >> reporter: in the case of al awlaki, they bugged a thumb drive he used to send messages including the wife's list. >> reporter: transmitter would be placed in the program that could send a message so he could be located. >> reporter: communications sent