Definitive pronouncements about the group are hazardous, since its communications with the outside world are fragmentary and its tactics and motivations remain murky. Even the group\u2019s leadership is a mystery. The Nigerian government has claimed to have killed Mr. Shekau at least three times, although there is wide disagreement here on whether Mr. Shekau or a secret successor is in charge.<\/p>\n
American intelligence officials say they have no reason to doubt the authenticity of the recent video or that the individual who appears in it is Mr. Shekau.<\/p>\n
Said to be in his mid-30s to his early 40s, Mr. Shekau was born in a remote village on the border with Niger, in the neighboring state of Yobe. When he was a young boy he was taken by his father for Quranic studies to a mallam, or \u201clearned one,\u201d\u009d in Maiduguri, a center of Islamic teaching. \u201cHe was the most troublesome of all of his students,\u201d\u009d the mallam\u2019s son recalled last week, outside his one-story mud-walled house in a dense neighborhood here. \u201cHe was arguing with the mallam all the time,\u201d\u009d said the teacher\u2019s son, Baba Fanani.<\/p>\n